ARM: ux500: Don't set plf ocr mask for SD/MMC device

The mmci host driver overrides platform ocr mask when a vmmc regulator
can be used. This is the case for sdi0(SD-card) and for sdi4(eMMC).
Thus it is pointless of specifing these mask and why we do remove them.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>