nb/intel/x4x/Kconfig: Don't fix CBFS_SIZE on i82801gx southbridge

The x4x northbridge can be paired with either an ICH7 (in the case of
g41) or an ICH10 (all other cases: g45, q45, p45, ...). Only ICH10
sometimes occurs with a descriptor, gbe and an ME region.

ICH7 is always descriptorless so it makes no sense to fix CBFS to
accommodate for those other objects.

Change-Id: I4a01dfdbce1807e44932a3ac812110382332abd8
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/19181
Tested-by: build bot (Jenkins)
Reviewed-by: Nico Huber <nico.h@gmx.de>

src/northbridge/intel/x4x/Kconfig

@@ -28,7 +28,7 @@ config NORTHBRIDGE_SPECIFIC_OPTIONS # dummy
 
 config CBFS_SIZE
 	hex
-	default 0x100000
+	default 0x100000 if !SOUTHBRIDGE_INTEL_I82801GX
 
 config BOOTBLOCK_NORTHBRIDGE_INIT
 	string