mmc: dw_mmc: add missing codes for runtime resume

The commit 64997de4fd17 ("mmc: dw_mmc: remove system PM callback") is
missing to call dw_mci_ctrl_reset(). This adds to call
dw_mci_ctrl_reset() and to handle error of clocks.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>