Revert "Mushu: Enable PCIe 1d.4 to enable dgpu"

This reverts commit 1408798637.

Reason for revert: Causing backlight issues in device.  Will reland after more debugging to figure out the root cause.

BUG=b:159370566
BRANCH=None
TEST=boot up device and make sure when kernel is booted, backlight comes up.

Change-Id: I643854c6c805d262539bbb482808e8c322059a49
Signed-off-by: Shelley Chen <shchen@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/42583
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

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

@@ -185,7 +185,6 @@ chip soc/intel/cannonlake
 				device i2c 1a on end
 			end
 		end #I2C #4
-		device pci 1d.4 on  end # PCI Express port 13
 		device pci 1e.3 on
 			chip drivers/spi/acpi
 				register "name" = ""CRFP""