Relax timer_rate to 19000.

timer_rate of 10000 provides better perf and better perf/W for some
workloads, but it causes regressions in very-low-power workloads
because of the sheer number of frequency changes and oscillations.

bug 23092353

Change-Id: If89cc06820ba8dead01afaff9c17e74b3104bb98
1 file changed