The aliases for dwmmc were placed in the SMDK5250 dts file but really
should be common for all exynos5250 boards.  Move it to the common CPU
file.
Signed-off-by: Doug Anderson <dianders@chromium.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>