arch/x86: Display MTRRs after MTRR update in postcar

Display the MTRRs after they have been updated during the postcar stage.

TEST=Build and run on Galileo Gen2

Change-Id: I1532250cacd363c1eeaf72edc6cb9e9268a11375
Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com>
Reviewed-on: https://review.coreboot.org/15991
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/arch/x86/exit_car.S

@@ -108,6 +108,11 @@ _start:
 	wrmsr
 #endif /* CONFIG_SOC_SETS_MSRS */
 
+	/* Display the MTRRs */
+#if IS_ENABLED(CONFIG_POSTCAR_CONSOLE)
+	call	soc_display_mtrrs
+#endif /* CONFIG_POSTCAR_CONSOLE */
+
 	/* Load and run ramstage. */
 	call	copy_and_run
 	/* Should never return. */