soc/intel/skylake: Enable MTRR check

Change a4b11e5c90 (soc/intel/skylake: Perform CPU MP Init
before FSP-S Init) dropped mtrr_check while re-organizing
code. Add the check back after MTRR setup is performed.

BUG=b:36656098
TEST=Verified that MTRR check is done after setup on poppy.

Change-Id: I440405c58c470ffa338be386d84870635530a031
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://review.coreboot.org/19609
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Philippe Mathieu-Daudé <philippe.mathieu.daude@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/soc/intel/skylake/cpu.c

@@ -523,6 +523,7 @@ static void soc_post_cpus_init(void *unused)
 {
 	if (mp_run_on_all_cpus(&x86_setup_mtrrs_with_detect, 1000) < 0)
 		printk(BIOS_ERR, "MTRR programming failure\n");
+	x86_mtrr_check();
 }
 
 int soc_skip_ucode_update(u32 current_patch_id, u32 new_patch_id)