EXYNOS5: DWMMC: Added FDT support for DWMMC

This patch adds FDT support for DWMMC, by reading the DWMMC node data
from the device tree and initialising DWMMC channels as per data
obtained from the node.

Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
Signed-off-by: Amar <amarendra.xt@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>