tsc: Change default tsc calibration method to pmtimer on EFI systems

tsc: Change default tsc calibration method to pmtimer on EFI systems

On efi systems, make pmtimer based tsc calibration the default over the
pit. This prevents Grub from hanging on Intel SoC systems that power gate
the pit.

Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Origin: upstream, https://git.savannah.gnu.org/cgit/grub.git/commit/?id=446794de8da4329ea532cbee4ca877bcafd0e534
Bug-Debian: https://bugs.debian.org/883193
Last-Update: 2017-12-01

Patch-Name: tsc_efi_default_to_pmtimer.patch

Gbp-Pq: Name tsc_efi_default_to_pmtimer.patch