mb/hp: Set CBFS_SIZE

Overwrite the default of 1 MiB with the actual bios region size
set in the stock IFD.

Allows to use payloads like TianoCore without manually touching
the CBFS_SIZE.

Change-Id: Ic1753a38212cc4961671fea11afe88265e73333b
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39073
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/hp/compaq_8200_elite_sff/Kconfig

@@ -19,6 +19,9 @@ config BOARD_SPECIFIC_OPTIONS
 	select INTEL_GMA_HAVE_VBT
 	select MAINBOARD_USES_IFD_GBE_REGION
 
+config CBFS_SIZE
+	default 0x2F0000
+
 config MAINBOARD_DIR
 	string
 	default "hp/compaq_8200_elite_sff"

src/mainboard/hp/z220_sff_workstation/Kconfig

@@ -30,6 +30,9 @@ config VBOOT_VBNV_OFFSET
 	hex
 	default 0x2a
 
+config CBFS_SIZE
+	default 0x570000
+
 config MAINBOARD_DIR
 	string
 	default "hp/z220_sff_workstation"