rk3288: kconfig: remove duplicate definition of SPL_MMC_SUPPORT

SPL_MMC_SUPPORT defined in rockchip top level Kconfig instead of
inside rk3288 and default to disable if ROCKCHIP_SPL_BACK_TO_BROM
defined.

Patch-cc: [email protected]

Change-Id: I77fcb2dda8afdf89684fc57cdc6e485a5840314c
Signed-off-by: Kever Yang <[email protected]>

Author: keveryang

arch/arm/mach-rockchip/rk3288/Kconfig

@@ -81,9 +81,6 @@ config SPL_LIBCOMMON_SUPPORT
 config SPL_LIBGENERIC_SUPPORT
 	default y
 
-config SPL_MMC_SUPPORT
-	default y
-
 config SPL_SERIAL_SUPPORT
 	default y