commonlib/region: expose subregion helper function

Export region_is_subregion() for determinig if a region is a child of
a parent region.

BUG=b:69614064

Change-Id: I6363fe4fdb33342f9d025a726ec7e17e87adf7e0
Signed-off-by: Aaron Durbn <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/22878
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
2 files changed