ARM: multi_v7_defconfig: enable CONFIG_MMC_DW_ROCKCHIP

Allows booting from SD/MMC on RK3288 and other platforms. Added here so I
can enable the board in the boot farm.
Signed-off-by: NOlof Johansson <olof@lixom.net>

arch/arm/configs/multi_v7_defconfig

@@ -353,6 +353,7 @@ CONFIG_MMC_MVSDIO=y
 CONFIG_MMC_SUNXI=y
 CONFIG_MMC_DW=y
 CONFIG_MMC_DW_EXYNOS=y
+CONFIG_MMC_DW_ROCKCHIP=y
 CONFIG_NEW_LEDS=y
 CONFIG_LEDS_CLASS=y
 CONFIG_LEDS_GPIO=y