nb/intel/x4x: Use common code for SMM in TSEG

This also caches the TSEG region and therefore increases MTRR usage
a little in some cases.

Currently SMRR msr's are not set on model_1067x and model_6fx since
this needs the MSRR enable bit and lock set in IA32_FEATURE_CONTROL.
This will be handled properly in the subsequent parallel mp init
patchset.

Tested on Intel DG41WV, resume from S3 still works fine.

Change-Id: I317c5ca34bd38c3d42bf0d4e929b2a225a8a82dc
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/25597
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/northbridge/intel/x4x/Kconfig b/src/northbridge/intel/x4x/Kconfig
index 1c65614..117ac03 100644
--- a/src/northbridge/intel/x4x/Kconfig
+++ b/src/northbridge/intel/x4x/Kconfig
@@ -28,6 +28,7 @@
 	select CACHE_MRC_SETTINGS
 	select POSTCAR_STAGE
 	select POSTCAR_CONSOLE
+	select SMM_TSEG
 
 config CBFS_SIZE
 	hex