mmc: sh_mmcif: Enable MMC_CAP2_NO_SD and MMC_CAP2_NO_SDIO

Enable the capabilities which tells the mmc core to prevent sending SD and
SDIO commands during card initialization. In this way, we can also remove
the validation of non-supported commands in the ->request() callback.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>