ARM: dts: Fix status property of mmc nodes for snow board

Commit e908d5c5

 ("ARM: dts: change status property of dwmmc nodes
for exynos5250") missed out handling the exynos5250 snow dts file.

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: Yuvaraj Kumar C D <yuvaraj.cd@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>