mmc: sh_mobile_sdhi: add ocr_mask option

In moving platforms from board files to DT, there still needs to be a way
to set the ocr_mask setting for the tmio driver during probe. Without this
setting, the probe will fail because the supported voltages are not known.

This patch will also traditional platform registration platforms to
migrate to DT.

Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>