mb/lenovo/T4xx: enable PEG device

Enable the PEG device in devicetree to expose the
device if any. This is already default behaviour
for T5xx series.

Change-Id: I16bd253ca96c4cdaad8a829f6490cec9e2599b5f
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/14448
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@googlemail.com>
diff --git a/src/mainboard/lenovo/t420s/devicetree.cb b/src/mainboard/lenovo/t420s/devicetree.cb
index ca02455..2376d64 100644
--- a/src/mainboard/lenovo/t420s/devicetree.cb
+++ b/src/mainboard/lenovo/t420s/devicetree.cb
@@ -39,7 +39,7 @@
 		device pci 00.0 on
 			subsystemid 0x17aa 0x21d2
 		end # host bridge
-		device pci 01.0 off end # NVIDIA Corporation GF119M [NVS 4200M]
+		device pci 01.0 on end # NVIDIA Corporation GF119M [NVS 4200M]
 		device pci 02.0 on
 			subsystemid 0x17aa 0x21d3
 		end # Integrated Graphics Controller