soc/intel/quark: Add monotonic timer support

Add the Kconfig value HAVE_MONOTONIC_TIMER and the routine to read the
TSC for the monotonic timer.  Simplify the routine to get the TSC
frequency.

TEST=Build and run on Galileo Gen2

Change-Id: I806fb864b01e39277bf2d6276254b0543930c2f6
Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com>
Reviewed-on: https://review.coreboot.org/18002
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Martin Roth <martinroth@google.com>
2 files changed