Add clk tracing to freq category

Upstream has clk_* in `/trace/events/clk.h' and clock_* `/trace/events/power.h'
for reporting clock events, and individual driver may pick either.

Bug: 73775767
Test: collect systrace
Change-Id: Id187e448a414cb2420b40d65ecf6219296d45172
Merged-In: Id187e448a414cb2420b40d65ecf6219296d45172