clk: qcom: gdsc: Remove global mutex lock in enable/disable callbacks

The global mutex lock which was introduced to correct a droop issue on
certain devices during multiple enable/disable of GDSCs is no longer a
requirement, so remove the same to avoid the GDSC lock being acquired
while holding clock global lock causing the deadlock scenario.

Change-Id: Idc674dea06935509524afb89602599902dd03c56
Signed-off-by: Odelu Kukatla <okukatla@codeaurora.org>