mips: mtmips: add two reference boards for mt7621

The mt7621_rfb board supports integrated giga PHYs plus one external
giga PHYs. It also has up to 512MiB DDR3, 16MB SPI-NOR, 3 mini PCI-e x1
slots, SDXC and USB.

The mt7621_nand_rfb board is almost the same as mt7621_rfb board, but it
uses NAND flash and SDXC is not available.

Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
diff --git a/arch/mips/mach-mtmips/mt7621/Kconfig b/arch/mips/mach-mtmips/mt7621/Kconfig
index 37d512c..008a28f 100644
--- a/arch/mips/mach-mtmips/mt7621/Kconfig
+++ b/arch/mips/mach-mtmips/mt7621/Kconfig
@@ -79,6 +79,26 @@
 choice
 	prompt "Board select"
 
+config BOARD_MT7621_RFB
+	bool "MediaTek MT7621 RFB (SPI-NOR)"
+	help
+	  The reference design of MT7621A (WS3010) booting from SPI-NOR flash.
+	  The board can be configured with DDR2 (64MiB~256MiB) or DDR3
+	  (128MiB~512MiB). The board has 16 MiB SPI-NOR flash, built-in MT7530
+	  GbE switch, 1 UART, 1 USB 2.0 host, 1 USB 3.0 host, 1 SDXC, 3 PCIe
+	  sockets, 1 RGMII to external GbE PHY, 2 audio jacks (in/out),
+	  JTAG pins and expansion GPIO pins.
+
+config BOARD_MT7621_NAND_RFB
+	bool "MediaTek MT7621 RFB (NAND)"
+	help
+	  The reference design of MT7621A (WS3010) booting from NAND flash.
+	  The board can be configured with DDR2 (64MiB~256MiB) or DDR3
+	  (128MiB~512MiB). The board has 128 MiB parallel NAND flash, built-in
+	  MT7530 GbE switch, 1 UART, 1 USB 2.0 host, 1 USB 3.0 host, 3 PCIe
+	  sockets, 1 RGMII to external GbE PHY, 2 audio jacks (in/out),
+	  JTAG pins and expansion GPIO pins.
+
 endchoice
 
 config SYS_CONFIG_NAME