arch/x86: unexpose postcar_frame_common_mtrrs()
The only caller is contained within the postcar_loader compilation unit.
Therefore, remove postcar_frame_common_mtrrs() from the global symbol
namespace.
Change-Id: I90d308669d13eb2bebf1eca4d47e3f3b4f178714
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41101
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>