ARM: renesas: Add R8A77970 V3MSK board and CPLD code

Add board code for the R8A77970 V3MSK board.
Add CPLD sysreset driver to the R-Car V3M SK board.
Extracted from a larger patch by Valentine Barshak.

Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Signed-off-by: Valentine Barshak <valentine.barshak@cogentembedded.com>
Signed-off-by: Hai Pham <hai.pham.ud@renesas.com>
Signed-off-by: Tam Nguyen <tam.nguyen.xa@renesas.com>
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
[Marek: Sync configs and board code with V3M Eagle, squash CPLD driver in]
diff --git a/doc/README.rmobile b/doc/README.rmobile
index ea170a2..524d839 100644
--- a/doc/README.rmobile
+++ b/doc/README.rmobile
@@ -35,6 +35,7 @@
 | R8A77965 M3-N | Renesas Electronics ULCB               | r8a77965_ulcb
 |---------------+----------------------------------------+-------------------
 | R8A77970 V3M  | Renesas Electronics Eagle              | r8a77970_eagle_defconfig
+| R8A77970 V3M  | Renesas Electronics V3MSK              | r8a77970_v3msk_defconfig
 |---------------+----------------------------------------+-------------------
 | R8A77995 D3   | Renesas Electronics Draak              | r8a77995_draak_defconfig
 '===============+========================================+===================