mb/google/drallion: Disable GBE in firmware for drallion variants

BUG: None
TEST: Build successful, checked the CBMEM log if 1f.6 is disabled with this patch

Signed-off-by: Thejaswani Putta <thejaswani.putta@intel.corp-partner.google.com>
Change-Id: I4e74b259ce8f5f70833dce94692dcbe33e8504db
Reviewed-on: https://review.coreboot.org/c/coreboot/+/35509
Reviewed-by: Mathew King <mathewk@chromium.org>
Reviewed-by: Bora Guvendik <bora.guvendik@intel.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/drallion/variants/sarien_cml/devicetree.cb

@@ -417,6 +417,6 @@ chip soc/intel/cannonlake
 		device pci 1f.3 on  end # Intel HDA
 		device pci 1f.4 on  end # SMBus
 		device pci 1f.5 on  end # PCH SPI
-		device pci 1f.6 on  end # GbE
+		device pci 1f.6 off end # GbE
 	end
 end