ARM: dts: msm: remove always on for sdhc reg on msmcobalt

The vdd and vdd io for SDHC can be turned off when not in use,
hence remove the always on setting and update the supported
voltage levels as per power grid.

Change-Id: I64059e1c440736884c7fea1a0096351b8b49f976
Signed-off-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>