odroid-c2: enable new Meson GX MMC driver in board defconfig

Enable new Meson GX MMC driver in Odroid C2 defconfig.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>

configs/odroid-c2_defconfig

@@ -14,7 +14,10 @@ CONFIG_DEFAULT_DEVICE_TREE="meson-gxbb-odroidc2"
 # CONFIG_CMD_SETEXPR is not set
 CONFIG_OF_CONTROL=y
 CONFIG_NET_RANDOM_ETHADDR=y
-# CONFIG_MMC is not set
+CONFIG_MMC=y
+CONFIG_DM_MMC=y
+CONFIG_MMC_MESON_GX=y
+CONFIG_CMD_MMC=y
 CONFIG_DM_ETH=y
 CONFIG_ETH_DESIGNWARE=y
 CONFIG_PINCTRL=y