ramips: add MT7620 pinmux bits for mdio as refclk

The MT7620 uses a 2 bit wide configuration of the mdio.

Signed-off-by: Michael Lee <igvtee@gmail.com>

target/linux/ramips/patches-4.4/0700-pinctrl-mt7620-mdio-as-refclk.patch

+--- a/arch/mips/include/asm/mach-ralink/mt7620.h
++++ b/arch/mips/include/asm/mach-ralink/mt7620.h
+@@ -114,9 +114,14 @@
+ #define MT7620_GPIO_MODE_WDT_MASK	0x3
+ #define MT7620_GPIO_MODE_WDT_SHIFT	21
+ 
++#define MT7620_GPIO_MODE_MDIO		0
++#define MT7620_GPIO_MODE_MDIO_REFCLK	1
++#define MT7620_GPIO_MODE_MDIO_GPIO	2
++#define MT7620_GPIO_MODE_MDIO_MASK	0x3
++#define MT7620_GPIO_MODE_MDIO_SHIFT	7
++
+ #define MT7620_GPIO_MODE_I2C		0
+ #define MT7620_GPIO_MODE_UART1		5
+-#define MT7620_GPIO_MODE_MDIO		8
+ #define MT7620_GPIO_MODE_RGMII1		9
+ #define MT7620_GPIO_MODE_RGMII2		10
+ #define MT7620_GPIO_MODE_SPI		11
+--- a/arch/mips/ralink/mt7620.c
++++ b/arch/mips/ralink/mt7620.c
+@@ -55,7 +55,10 @@ static int dram_type;
+ static struct rt2880_pmx_func i2c_grp[] =  { FUNC("i2c", 0, 1, 2) };
+ static struct rt2880_pmx_func spi_grp[] = { FUNC("spi", 0, 3, 4) };
+ static struct rt2880_pmx_func uartlite_grp[] = { FUNC("uartlite", 0, 15, 2) };
+-static struct rt2880_pmx_func mdio_grp[] = { FUNC("mdio", 0, 22, 2) };
++static struct rt2880_pmx_func mdio_grp[] = {
++	FUNC("mdio", MT7620_GPIO_MODE_MDIO, 22, 2),
++	FUNC("refclk", MT7620_GPIO_MODE_MDIO_REFCLK, 22, 2),
++};
+ static struct rt2880_pmx_func rgmii1_grp[] = { FUNC("rgmii1", 0, 24, 12) };
+ static struct rt2880_pmx_func refclk_grp[] = { FUNC("spi refclk", 0, 37, 3) };
+ static struct rt2880_pmx_func ephy_grp[] = { FUNC("ephy", 0, 40, 5) };
+@@ -92,7 +95,8 @@ static struct rt2880_pmx_group mt7620a_p
+ 	GRP("uartlite", uartlite_grp, 1, MT7620_GPIO_MODE_UART1),
+ 	GRP_G("wdt", wdt_grp, MT7620_GPIO_MODE_WDT_MASK,
+ 		MT7620_GPIO_MODE_WDT_GPIO, MT7620_GPIO_MODE_WDT_SHIFT),
+-	GRP("mdio", mdio_grp, 1, MT7620_GPIO_MODE_MDIO),
++	GRP_G("mdio", mdio_grp, MT7620_GPIO_MODE_MDIO_MASK,
++		MT7620_GPIO_MODE_MDIO_GPIO, MT7620_GPIO_MODE_MDIO_SHIFT),
+ 	GRP("rgmii1", rgmii1_grp, 1, MT7620_GPIO_MODE_RGMII1),
+ 	GRP("spi refclk", refclk_grp, 1, MT7620_GPIO_MODE_SPI_REF_CLK),
+ 	GRP_G("pcie", pcie_rst_grp, MT7620_GPIO_MODE_PCIE_MASK,