mips: mtmips: add two reference boards for mt7620

The mt7620_rfb board supports integrated 10/100M PHYs plus two external
giga PHYs. It also has 8MB SPI-NOR, mini PCI-e x1 slot, SDHC and USB.

The mt7620_mt7530_rfb boards supports an external MT7530 giga switch and a
16MB SPI-NOR flash.

Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
diff --git a/arch/mips/mach-mtmips/mt7620/Kconfig b/arch/mips/mach-mtmips/mt7620/Kconfig
index aa7cf1d..5db83eb 100644
--- a/arch/mips/mach-mtmips/mt7620/Kconfig
+++ b/arch/mips/mach-mtmips/mt7620/Kconfig
@@ -7,6 +7,21 @@
 choice
 	prompt "Board select"
 
+config BOARD_MT7620_RFB
+	bool "MediaTek MT7620 RFB"
+	help
+	  The reference design of MT7620A (WS2120). The board has 64 MiB DDR2,
+	  8 MiB SPI-NOR flash, 1 built-in 6 port switch (two GE PHYs and five
+	  FE PHYs,one port can be configured to use either FE PHY or GE PHY),
+	  1 UART, 1 USB host, 1 SDXC, 1 PCIe socket and JTAG pins.
+
+config BOARD_MT7620_MT7530_RFB
+	bool "MediaTek MT7620-MT7530 RFB"
+	help
+	  The reference design of MT7620DA (MTKC712). The board has 64 MiB
+	  intergrated DDR2 KGD, 16 MiB SPI-NOR flash, an external 5-port giga
+	  switch MT7530 and 1 UART.
+
 endchoice
 
 choice
@@ -51,4 +66,6 @@
 	default 6 if CPU_FREQ_600MHZ
 	default 7 if CPU_FREQ_620MHZ
 
+source "board/mediatek/mt7620/Kconfig"
+
 endif