realtek: rtl838x: Enable MDIO_GPIO driver

The mdio-gpio driver is required to support early revision of RTL8380M
slicon (rev A) where the auxilairy MDIO controller does not function
correctly. Add this driver to the rtl838x kernel so devices with old
SoCs are also able to function correctly.

Signed-off-by: Sander Vanheule <sander@svanheule.net>

target/linux/realtek/rtl838x/config-6.6

@@ -128,9 +128,11 @@ CONFIG_LIBFDT=y
 CONFIG_LOCK_DEBUGGING_SUPPORT=y
 CONFIG_MACH_REALTEK_RTL=y
 CONFIG_MARVELL_PHY=y
+CONFIG_MDIO_BITBANG=y
 CONFIG_MDIO_BUS=y
 CONFIG_MDIO_DEVICE=y
 CONFIG_MDIO_DEVRES=y
+CONFIG_MDIO_GPIO=y
 CONFIG_MDIO_I2C=y
 CONFIG_MDIO_REALTEK_OTTO_AUX=y
 CONFIG_MDIO_SMBUS=y