msm: kgsl: add power tracepoints

Add kgsl_clk, kgsl_bus, kgsl_irq, kgsl_rail, kgsl_pwrlevel,
kgsl_pwr_set_state and kgsl_pwr_request_state trace
events.

Change-Id: I3bf246f350b1208123ab9a33c08495cea9c533eb
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>