mb/lenovo/x200: Fix X301 override tree

`chip` entries always need a device node below them to actually get
hooked up.

Change-Id: Ib9e6019b6f316c1b176da1592514dcdcaf8c505a
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/57473
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/lenovo/x200/variants/x301/overridetree.cb

@@ -8,6 +8,8 @@ chip northbridge/intel/gm45
 			register "pcie_power_limits" = "{ { 10, 0 }, { 10, 0 }, { 10, 0 }, { 0, 0 }, { 0, 0 }, { 0, 0 } }"
 			# x301 has no Express Card slot.
 			register "pcie_hotplug_map" = "{ 0, 0, 0, 0, 0, 0, 0, 0 }"
+
+			device pci 1c.0 on end # PCIe Port #1
 		end
 	end
 end