mb/google/fatcat: Remove redundant iGPU device entry

The iGPU device is enabled by default in the Pantherlake chipset
configuration. Remove the redundant device entry in the Fatcat
devicetree.

This change ensures that the iGPU remains enabled without explicit
configuration in the board-specific devicetree.

TEST=Able to build google/fatcat and able to see firmware and OS
display/UI.

Change-Id: I9a2ec9b47acb389f5bb6b30e61352aaefa327328
Signed-off-by: Subrata Banik <subratabanik@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/84876
Reviewed-by: Jayvik Desai <jayvik@google.com>
Reviewed-by: Pranava Y N <pranavayn@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Eric Lai <ericllai@google.com>

src/mainboard/google/fatcat/variants/baseboard/fatcat/devicetree.cb

@@ -53,7 +53,6 @@ chip soc/intel/pantherlake
 	register "pch_hda_sdi_enable" = "{ true, false }"
 
 	device domain 0 on
-		device ref igpu on end
 		device ref dtt on end
 		device ref npu on end
 		device ref xhci on end