mmc: sdhci-esdhc-imx: restore watermark level setting after resume

Currently, we config the watermark_level register only in probe.
This will cause the mmc write operation timeout issue after system
resume back in LPSR mode. Because in LPSR mode, after system resume
back, the watermark_level register(0x44) changes to 0x08000880, which
set the write watermark level as 0, and set the read watermark level
as 128. This value is incorrect.

This patch restores the setting of watermark level register after
system resume back.

Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>