Newer x86 processors have a core invariant tsc. On these systems it is
safe to use the rtdtsc instruction as a monotonic timer. This commit
adds a new function to the opal timer code to check if the timer
backend is monotonic. On x86 it checks the appropriate bit and on
other architectures it parrots back the OPAL_TIMER_MONOTONIC value.
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
a718743a5c