lib/fmap: Cache FMAP in cbmem

For platform independend exposure of FMAP through a kernel module
cache the FMAP in CBMEM. In addition add a pointer in coreboot tables
pointing to the introduced CBMEM area.

To not waste the allocated DRAM, use the cached CBMEM in RAM enabled
stages if possible.

Tested on qemu using
https://github.com/9elements/linux/commits/google_firmware_fmap2

Tested on QEMU and Supermicro X11SSH-TF.

Change-Id: I4e01c573c3edfa34dbba5fe7604d4f6e18b584d5
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/35377
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Julius Werner <jwerner@chromium.org>

src/commonlib/include/commonlib/cbmem_id.h

@@ -76,6 +76,7 @@
 #define CBMEM_ID_ROM1		0x524f4d31
 #define CBMEM_ID_ROM2		0x524f4d32
 #define CBMEM_ID_ROM3		0x524f4d33
+#define CBMEM_ID_FMAP		0x464d4150
 
 #define CBMEM_ID_TO_NAME_TABLE				 \
 	{ CBMEM_ID_ACPI,		"ACPI       " }, \
@@ -134,5 +135,6 @@
 	{ CBMEM_ID_ROM0,		"VGA ROM #0 "}, \
 	{ CBMEM_ID_ROM1,		"VGA ROM #1 "}, \
 	{ CBMEM_ID_ROM2,		"VGA ROM #2 "}, \
-	{ CBMEM_ID_ROM3,		"VGA ROM #3 "},
+	{ CBMEM_ID_ROM3,		"VGA ROM #3 "}, \
+	{ CBMEM_ID_FMAP,		"FMAP       "},
 #endif /* _CBMEM_ID_H_ */

src/commonlib/include/commonlib/coreboot_tables.h

@@ -89,6 +89,7 @@ enum {
 	LB_TAG_VBOOT_WORKBUF		= 0x0034,
 	LB_TAG_MMC_INFO			= 0x0035,
 	LB_TAG_TCPA_LOG			= 0x0036,
+	LB_TAG_FMAP			= 0x0037,
 	LB_TAG_CMOS_OPTION_TABLE	= 0x00c8,
 	LB_TAG_OPTION			= 0x00c9,
 	LB_TAG_OPTION_ENUM		= 0x00ca,