board-msm7x30: mmc: Fix high current consumption during suspend.

With SANDisk class-4 4GB SD card, the current drain on Vdd (LDO5)
rail is observed to be ~8mA after the first resume.
It continues to remain ~8mA even during subsequent suspend states.

Fix this by switching off the Vdd to the card on suspend
and switching on the same on resume.

CRs-Fixed: 325730
Change-Id: I3d52b8aeec9cbb643274390d69137890e1d576bf
Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>