ARM: sunxi: remove bare default for CONFIG_MMC

The bare default entry is wrong.  Just remove it since the (real)
entry in drivers/mmc/Kconfig has "default ARM || PPC || SANDBOX".
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NMarek Vasut <marex@denx.de>

board/sunxi/Kconfig

@@ -318,10 +318,6 @@ config OLD_SUNXI_KERNEL_COMPAT
 	Set this to enable various workarounds for old kernels, this results in
 	sub-optimal settings for newer kernels, only enable if needed.
 
-config MMC
-	depends on !UART0_PORT_F
-	default y if ARCH_SUNXI
-
 config MMC0_CD_PIN
 	string "Card detect pin for mmc0"
 	default "PF6" if MACH_SUN8I_A83T || MACH_SUN8I_H3 || MACH_SUN50I