mb/google/hatch: Give first NIC in Puff idx 1 for vpd

The format for VPD has changed s.t. the first NIC should
always have a zero concat to the end. drivers/net supports
this with the workaround of setting the idx to 1.

The longer term fix is to adjust all the respective boards
to shift back by one and adjust drivers/net friends to
remove the 'special casing' of idx == 0.

Background:
https://chromeos.google.com/partner/dlm/docs/factory/vpd.html#field-ethernet_macn

BUG=b:152157720
BRANCH=none
TEST=none

Change-Id: I510428c555b92398a5199b346dffb85d38495d74
Signed-off-by: Edward O'Callaghan <quasisec@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39768
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Sam McNally <sammc@google.com>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/mainboard/google/hatch/variants/puff/overridetree.cb

@@ -283,6 +283,7 @@ chip soc/intel/cannonlake
 				register "stop_delay_ms" = "12" # NIC needs time to quiesce
 				register "stop_off_delay_ms" = "1"
 				register "has_power_resource" = "1"
+				register "device_index" = "1"
 				device pci 00.0 on end
 			end
 		end # FSP requires func0 be enabled.