drver:soc:llcc_perfmon: qdss clk node control

qdss clock needs to be enabled on llcc_perfmon counter to function.
Enable/disable clock on Start/Stop llcc_perfmon commands.

Change-Id: Ic75119a08f0be1deadcdc694f27098296bfda07e
Signed-off-by: Avinash Philip <avinashp@codeaurora.org>