libc: remove obsolete CLOCK_REALTIME_HR and CLOCK_MONOTONIC_HR

Add CLOCK_MONOTONIC_RAW, CLOCK_REALTIME_COARSE, and CLOCK_MONOTONIC_COARSE
as supported by recent linux kernels.

(cherry-pick of 60e5144ca312b210b54ac8e6966108da0c97ff80.)

Bug: 8895727
Change-Id: If79a4d05d1301108f49a37588f9416c4be19277a
1 file changed