Revert "ARM: ux500: Stop passing MMC's platform data for Device Tree boots"

This reverts commit 49c12951.

The special settings for the SD/MMC card parameters that are not
yet fully agreed upon how to encode into the device tree went missing
with this commit. We need to first put it into the device tree,
and then remove the platform data.

Cc: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>