commonlib: Add CBFS_TYPE_BOOTBLOCK

Add CBFS_TYPE_BOOTBLOCK to allow accessing the bootblock as a CBFS file.

BUG=N/A
TEST=build

Change-Id: Ibb03ac3a6cd8711e0402e47335bb8e110c6ef61a
Signed-off-by: Wim Vervoorn <wvervoorn@eltan.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41824
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-by: Frans Hendriks <fhendriks@eltan.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/commonlib/bsd/include/commonlib/bsd/cbfs_serialized.h

@@ -21,6 +21,7 @@
 
 #define CBFS_TYPE_DELETED    0x00000000
 #define CBFS_TYPE_DELETED2   0xffffffff
+#define CBFS_TYPE_BOOTBLOCK  0x01
 #define CBFS_TYPE_STAGE      0x10
 #define CBFS_TYPE_SELF       0x20
 #define CBFS_TYPE_FIT        0x21