power: reset: Add msm restart support

Add support for restart and poweroff functionality present on MSM chipsets
with the MPM2 ps-hold hardware.

Change-Id: I83e9b06febeb01bfdd13defb43f033ccb7e5735b
Tested-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>
Git-commit: 78be3176c4335b8ff3d9625ed3fc571e7d2ba8f4
Git-Repo: git://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/


Signed-off-by: Abhimanyu Kapur <abhimany@codeaurora.org>