doc: Migrate Renesas board docs to rst

Some of the information in README.rmobile is obsolete, references
defconfigs which no longer exist in u-boot or has broken links. The
information which is still relevant is moved into the reStructuredText
documentation under `doc/board/renesas`, and `doc/README.rmobile` is
dropped.

The list of boards in `doc/board/renesas` is converted into a table so
it's easier to see which defconfig to use. The list is expanded based on
reviewing the current u-boot code and the contents of the eLinux wiki
[1] [2].

[1]: https://elinux.org/R-Car
[2]: https://elinux.org/RZ-G

Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/doc/board/renesas/renesas.rst b/doc/board/renesas/renesas.rst
index 04dee8d..7d961e8 100644
--- a/doc/board/renesas/renesas.rst
+++ b/doc/board/renesas/renesas.rst
@@ -9,37 +9,230 @@
 This document describes the information about Renesas supported boards
 and their usage steps.
 
-Renesas boards
---------------
+Renesas SoC based boards
+------------------------
 
 Renesas is a SoC solutions provider for automotive and industrial applications.
 
-U-Boot supports several Renesas SoC families:
+.. list-table:: Supported Renesas SoC based boards
+   :widths: 10, 25, 15, 10, 25
+   :header-rows: 1
+
+   * - Family
+     - Board
+     - SoC
+     - Arch
+     - defconfig
+
+   * - R2D
+     - R2D-PLUS
+     - SH7751
+     - sh
+     - r2dplus_defconfig
+
+   * - RZ/A1
+     - GR-PEACH
+     - R7S72100 (RZ/A1H)
+     - arm
+     - grpeach_defconfig
+
+   * - R-Car Gen2
+     - Lager
+     - R8A7790 (H2)
+     - arm
+     - lager_defconfig
+
+   * -
+     - Stout
+     - R8A7790 (H2)
+     - arm
+     - stout_defconfig
+
+   * -
+     - Koelsch
+     - R8A7791 (M2-W)
+     - arm
+     - koelsch_defconfig
+
+   * -
+     - Porter
+     - R8A7791 (M2-W)
+     - arm
+     - porter_defconfig
+
+   * -
+     - Blanche
+     - R8A7792 (V2H)
+     - arm
+     - blanche_defconfig
+
+   * -
+     - Gose
+     - R8A7793 (M2-N)
+     - arm
+     - gose_defconfig
+
+   * -
+     - Alt
+     - R8A7794 (E2)
+     - arm
+     - alt_defconfig
+
+   * -
+     - Silk
+     - R8A7794 (E2)
+     - arm
+     - silk_defconfig
+
+   * - R-Car Gen3
+     - Salvator-X(S)
+     - R8A77951 (H3)
+     - arm64
+     - rcar3_salvator-x_defconfig
+
+   * -
+     - ULCB
+     - R8A77951 (H3)
+     - arm64
+     - rcar3_ulcb_defconfig
+
+   * -
+     - Salvator-X(S)
+     - R8A77960 (M3-W)
+     - arm64
+     - rcar3_salvator-x_defconfig
+
+   * -
+     - ULCB
+     - R8A77960 (M3-W)
+     - arm64
+     - rcar3_ulcb_defconfig
+
+   * -
+     - Salvator-X(S)
+     - R8A77965 (M3-N)
+     - arm64
+     - rcar3_salvator-x_defconfig
+
+   * -
+     - ULCB
+     - R8A77965 (M3-N)
+     - arm64
+     - rcar3_ulcb_defconfig
+
+   * -
+     - Eagle
+     - R8A77970 (V3M)
+     - arm64
+     - r8a77970_eagle_defconfig
+
+   * -
+     - V3MSK
+     - R8A77970 (V3M)
+     - arm64
+     - r8a77970_v3msk_defconfig
+
+   * -
+     - Condor
+     - R8A77980 (V3H)
+     - arm64
+     - r8a77980_condor_defconfig
+
+   * -
+     - V3HSK
+     - R8A77980 (V3H)
+     - arm64
+     - r8a77980_v3hsk_defconfig
+
+   * -
+     - Ebisu
+     - R8A77990 (E3)
+     - arm64
+     - r8a77990_ebisu_defconfig
+
+   * -
+     - Draak
+     - R8A77995 (D3)
+     - arm64
+     - r8a77995_draak_defconfig
+
+   * - R-Car Gen4
+     - Falcon
+     - R8A779A0 (V3U)
+     - arm64
+     - r8a779a0_falcon_defconfig
+
+   * -
+     - Spider
+     - R8A779F0 (S4)
+     - arm64
+     - r8a779f0_spider_defconfig
+
+   * -
+     - White Hawk
+     - R8A779G0 (V4H)
+     - arm64
+     - r8a779g0_whitehawk_defconfig
+
+   * - RZ/G2 Family
+     - Beacon EmbeddedWorks RZ/G2M SoM
+     - R8A774A1 (RZ/G2M)
+     - arm64
+     - rzg2_beacon_defconfig
+
+   * -
+     - HopeRun HiHope RZ/G2M
+     - R8A774A1 (RZ/G2M)
+     - arm64
+     - hihope_rzg2_defconfig
+
+   * -
+     - Beacon EmbeddedWorks RZ/G2N SoM
+     - R8A774B1 (RZ/G2N)
+     - arm64
+     - rzg2_beacon_defconfig
+
+   * -
+     - HopeRun HiHope RZ/G2N
+     - R8A774B1 (RZ/G2N)
+     - arm64
+     - hihope_rzg2_defconfig
+
+   * -
+     - Silicon Linux RZ/G2E evaluation kit (EK874)
+     - R8A774C0 (RZ/G2E)
+     - arm64
+     - silinux_ek874_defconfig
+
+   * -
+     - Beacon EmbeddedWorks RZ/G2H SoM
+     - R8A774E1 (RZ/G2H)
+     - arm64
+     - rzg2_beacon_defconfig
+
+   * -
+     - HopeRun HiHope RZ/G2H
+     - R8A774E1 (RZ/G2H)
+     - arm64
+     - hihope_rzg2_defconfig
+
+   * - :doc:`RZ/N1 Family <rzn1>`
+     - Schneider RZ/N1D board
+     - R9A06G032 (RZ/N1D)
+     - arm64
+     - rzn1_snarc_defconfig
+
+   * -
+     - Schneider RZ/N1S board
+     - R9A06G033 (RZ/N1S)
+     - arm64
+     - rzn1_snarc_defconfig
+
+Build
+-----
+
+Locate the appropriate defconfig in the table above. Then apply standard build
+procedure::
 
-* R-Car Gen2 (32-bit)
-    - Blanche board
-    - Gose board
-    - Koelsch board
-    - Lager board
-    - Silk board
-    - Porter board
-    - Stout board
-* R-Car Gen3 (64-bit)
-    - Condor board
-    - Draak board
-    - Eagle board
-    - Ebisu board
-    - Salvator-X and Salvator-XS boards
-    - ULCB board
-* R-Car Gen4 (64-bit)
-    - Falcon board
-    - Spider board
-    - Whitehawk board
-* RZ/A1 (32-bit)
-    - GR-PEACH board
-* RZ/G
-    - Beacon-rzg2 board
-    - Hihope-rzg2 board
-    - ek874 board
-* RZ/N1 (32-bit)
-    - Schneider rzn1-snarc board
+    make <board_defconfig>
+    make