mmc: sh_mmcif: Fix suspend process

The clock should be enable when SDHI registers are accessed.

Signed-off-by: Koji Matsuoka <koji.matsuoka.xm@renesas.com>
Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
(cherry picked from commit 5afc30fc

)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>