1.Remove clock functions from some tests that don't need them.
2.In some memory pool tests and coherency tests, timer-based kernel
delay isn't reliable, use pinned host based notification instead.
3.Add CHECK_PCIE_ATOMICS_SUPPORT before some tests.
4.catch/unit/memory/hipMemoryAllocateCoherent.cc is removed
as it is useless and originally excluded in building.
5.Some tests can still pass even if clock rate =0, thus they
will be kept as is.
6.Some logic and format improvement in some tests.
Change-Id: I6b3c6bf54c61cffd45cd6f17c75998f751b75725
Sang, Tao
SrinivasaRao