cpu/intel/sandybridge: Put stage cache into TSEG

TSEG is not accessible in ring 0 after it is locked in ramstage, in
contrast with cbmem which remains accessible. Assuming SMM does not
touch the cache this is a good region to cache stages.

The code is mostly copied from src/cpu/intel/haswell.

TESTED on Thinkpad X220: on a cold boot the stage cache gets created
and on S3 the cached ramstage gets properly used.

Change-Id: Ifd8f939416b1712f6e5c74f544a5828745f8c2f2
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/23592
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
diff --git a/src/cpu/intel/model_206ax/Kconfig b/src/cpu/intel/model_206ax/Kconfig
index f16b119..b30cfa1 100644
--- a/src/cpu/intel/model_206ax/Kconfig
+++ b/src/cpu/intel/model_206ax/Kconfig
@@ -22,6 +22,7 @@
 	#select AP_IN_SIPI_WAIT
 	select TSC_SYNC_MFENCE
 	select CPU_INTEL_COMMON
+	select CACHE_RELOCATED_RAMSTAGE_OUTSIDE_CBMEM
 
 config BOOTBLOCK_CPU_INIT
 	string
@@ -35,4 +36,13 @@
 	hex
 	default 0x800000
 
+config SMM_RESERVED_SIZE
+	hex
+	default 0x100000
+
+# Intel Enhanced Debug region must be 4MB
+config IED_REGION_SIZE
+	hex
+	default 0x400000
+
 endif