msm: mdss: restore mdss register when clocks are turned on

When MDSS idle power collapse feature is enabled, MDSS GDSC can be
turned off for idle screen usecases. As a result, whenever MDSS
GDSC is turned back on, all MDSS registers need to be restored.
Current implementation restores this as part of bus bandwidth control
API which is only called whenever interface clocks are turned on.
However, the correct approach is to restore the hardware state whenever
any new register programming needs to be done. Therefore, move the
call to restore MDSS state from the bus bandwidth control function over
to the MDSS clock control function.

Change-Id: I85c934b8050b217253be98d9630ef922e76b6216
Signed-off-by: Aravind Venkateswaran <aravindh@codeaurora.org>