ARM: dts: msm: Update the regulator name to pm_gold

Make sure that the regulator name matches the regulator
handle. Also, fix the pmic handle for s5.

Change-Id: Id39bcbbb9da80bbec4b2bc7494d20dcb70e8163b
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>