sdhci: Do not power off the mmc card when entering in S3.

sdhci: Do not power off the mmc card when entering in S3.

BZ: 15061

Avoid enabling / disabling the regulator on suspend / resume.
The attached card shall remain powered by the regulator.

Change-Id: I5c848d911a27e9b0d19c5a37cf4ae60bcab77ccf
Signed-off-by: Aymen Zayet <aymenx.zayet@intel.com>
Reviewed-on: http://android.intel.com:8080/25380
Reviewed-by: Champciaux, NicolasX <nicolasx.champciaux@intel.com>
Tested-by: Champciaux, NicolasX <nicolasx.champciaux@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>