bionic: benchmark: add clock_getres performance tests

Provide a means to check vdso kernel performance for all reasoned
combinations of clock_getres, same set of ids as clock_gettime.

Add to suites/vdso.xml

Test: /data/nativetest{64}/bionic-benchmarks-tests/bionic-benchmarks-tests
      /data/benchmarktest{64}/bionic-benchmarks/bionic-benchmarks \
        --bionic_xml=vdso.xml --benchmark_filter=BM_time_clock_getres*
Bug: 63737556
Change-Id: I11ea200f67aec2a2f6ad9284960f2941298da222