northbridge/intel/x4x: transition away from device_t

Replace the use of the old device_t definition inside
northbridge/intel/x4x.

Change-Id: I65cd02eacf57cb41ded434582ca6e9d9f655e6ea
Signed-off-by: Antonello Dettori <dev@dettori.io>
Reviewed-on: https://review.coreboot.org/16472
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
2 files changed