msm: kgsl: Save and restore the power ctrl_flags during recovery

Power ctrl_flags will prevent the GPU power collapse when the
user has overwritten the force_rail_on, force_clk_on etc. This
will result into GPU wakeup problems in case power collapse
hasn’t happened during the hang recovery.

Change-Id: Ib1e86bbb70b2b71b8f8820692d13ce3ab6200db0
Signed-off-by: Hareesh Gundu <hareeshg@codeaurora.org>