Revert "mmc: mmcblk: Add support for deferred SD bus resume"

This reverts commit bc4dc52f178828e0000ce857f9a97fd8912c8e85.

Adds which hasn't built for awhile, so remove it.

Change-Id: Ife20b1b155ffe9afb3f0c5223727f7b8bd799d15
Signed-off-by: John Stultz <john.stultz@linaro.org>
(cherry picked from commit fe20b1b155ffe9afb3f0c5223727f7b8bd799d15)