mmc: sdhci-msm: Enable controller power save feature

Enable power save feature within controller by setting bit 1
in vendor specific register (0x10C). This allows controller to
disable SD clock when bus is idle to save power.

Change-Id: I916a5a414adb3f21dc3a75f3f86c3a81d6956dc8
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
[xiaonian@codeaurora.org: fix trivial merge conflict]
Signed-off-by: Xiaonian Wang <xiaonian@codeaurora.org>