mb/gigabyte/ga-g41m-es2l: Add PEG to devicetree

Change-Id: Icebf0eea4e1fee6d15ba3f1a080cbc40b42fd733
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41865
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/mainboard/gigabyte/ga-g41m-es2l/devicetree.cb

@@ -14,6 +14,7 @@ chip northbridge/intel/x4x		# Northbridge
 		device pci 0.0 on		# Host Bridge
 			subsystemid 0x1458 0x5000
 		end
+		device pci 1.0 on end		# PEG
 		device pci 2.0 on		# Integrated graphics controller
 			subsystemid 0x1458 0xd000
 		end