nb/intel/i945: Use common SMM_TSEG code

Use the common SMM_TSEG code to relocate the smihandler to TSEG.

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

This fixes S3 resume being broken introduced by CB:25594
"sb/intel/i82801gx: Use common Intel SMM code".

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 d945gclf and Lenovo Thinkpad X60.

Change-Id: I0e6374746c3df96ce16f1c4a177af12747d6c1a9
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/25595
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/northbridge/intel/i945/Kconfig b/src/northbridge/intel/i945/Kconfig
index 549f4df..92bf652 100644
--- a/src/northbridge/intel/i945/Kconfig
+++ b/src/northbridge/intel/i945/Kconfig
@@ -29,6 +29,7 @@
 	select HAVE_VGA_TEXT_FRAMEBUFFER if MAINBOARD_DO_NATIVE_VGA_INIT
 	select POSTCAR_STAGE
 	select POSTCAR_CONSOLE
+	select SMM_TSEG
 
 config NORTHBRIDGE_INTEL_SUBTYPE_I945GC
 	def_bool n