msm: 8930: sd card's regulator can be turned off on new hardware

All 8930 platform boards using the 1.2 SoC have been reworked so that
the sd card detect line's esd circuit is no longer powered by the sd
card's voltage regulator. So this means we can turn the regulator off
to save power without affecting the sd card detect functionality. This
change to the boards will be true for newer versions of the SoC too.

Change-Id: Iab5b87f3d00414668ea71aa6e87bd675a035ab59
Signed-off-by: Krishna Konda <kkonda@codeaurora.org>