soc/amd/stoney: Expand the SMM region for cache

Currently the data to be put to cache region is 0x14FF90. With the
limit size 0x150000, the data for S3 can not be put into. So we expand
it a little.

Change-Id: If6b03b713059c54c7dae8f2db0f6426d8aa1aab1
Signed-off-by: Zheng Bao <fishbaozi@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/69782
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/amd/stoneyridge/Kconfig

@@ -260,7 +260,7 @@ config SMM_TSEG_SIZE
 
 config SMM_RESERVED_SIZE
 	hex
-	default 0x150000
+	default 0x160000
 
 config SMM_MODULE_STACK_SIZE
 	hex