cpu/amd/agesa: Use common MRC_CACHE code to save S3 data

Use the common code to save data for fast boot or S3 resume.
An notable improvement that comes with this, is that the same 4K page
is not rewritten all the time. This prolongs the hardware's life.

TESTED on pcengines/apu1 and lenovo/g505s: S3 resume works fine.

Change-Id: I0f4f36dcead52a6c550fb5e606772e0a99029872
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44295
Reviewed-by: Mike Banon <mikebdp2@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-by: Michał Żygowski <michal.zygowski@3mdeb.com>

src/cpu/amd/agesa/Kconfig

@@ -13,6 +13,7 @@ config CPU_AMD_AGESA
 	select LAPIC_MONOTONIC_TIMER
 	select SPI_FLASH if HAVE_ACPI_RESUME
 	select SSE2
+	select CACHE_MRC_SETTINGS
 
 if CPU_AMD_AGESA
 
@@ -44,14 +45,6 @@ config ENABLE_MRC_CACHE
 	  Try to restore memory training results
 	  from non-volatile memory.
 
-config S3_DATA_POS
-	hex
-	default 0xFFFF0000
-
-config S3_DATA_SIZE
-	int
-	default 4096
-
 endif # CPU_AMD_AGESA
 
 source "src/cpu/amd/agesa/family14/Kconfig"

src/cpu/amd/agesa/Makefile.inc

@@ -3,18 +3,3 @@
 subdirs-$(CONFIG_CPU_AMD_AGESA_FAMILY14) += family14
 subdirs-$(CONFIG_CPU_AMD_AGESA_FAMILY15_TN) += family15tn
 subdirs-$(CONFIG_CPU_AMD_AGESA_FAMILY16_KB) += family16kb
-
-ifeq ($(CONFIG_HAVE_ACPI_RESUME), y)
-
-$(obj)/coreboot_s3nv.rom: $(obj)/config.h
-	echo "    S3 NVRAM   $(CONFIG_S3_DATA_POS) (S3 storage area)"
-	# force C locale, so cygwin awk doesn't try to interpret the 0xff below as UTF-8 (or worse)
-	printf %d $(CONFIG_S3_DATA_SIZE) | LC_ALL=C awk '{for (i=0; i<$$1; i++) {printf "%c", 255}}' > $@.tmp
-	mv $@.tmp $@
-
-cbfs-files-y += s3nv
-s3nv-file := $(obj)/coreboot_s3nv.rom
-s3nv-position := $(CONFIG_S3_DATA_POS)
-s3nv-type := raw
-
-endif # CONFIG_HAVE_ACPI_RESUME == y