asus/k8v-x: set superio ROM ctrl reg to enable writes

This is required for flashrom to work...

Change-Id: Icc0a52e0ca103c897d96fa8f3cf83b30780c7b49
Signed-off-by: Urja Rannikko <urjaman@gmail.com>
Reviewed-on: http://review.coreboot.org/12349
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

src/mainboard/asus/k8v-x/devicetree.cb

@@ -82,6 +82,7 @@ chip northbridge/amd/amdk8/root_complex		# Root complex
               device pnp 2e.b on		# Hardware monitor
                 io 0x60 = 0x290
                 irq 0x70 = 0
+                irq 0x24 = 0x28			# Global CR24 change bit3: MEMW# Enable
               end
             end
           end