mb/google/nissa/var/dirks: Add ACPI DmaProperty for Ethernet device

Add ACPI DmaProperty for Ethernet device to support untrusted PCIe
port verification.

BUG=b:398872682
TEST=cat /sys/devices/pci0000:00/0000:00:1c.0/0000:01:00.0/untrusted
     returned 1

Change-Id: I24d5f637f1349aace0fba0640c8e72ffc3401de9
Signed-off-by: Ivy Jian <ivy.jian@quanta.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/87197
Reviewed-by: Eric Lai <ericllai@google.com>
Reviewed-by: Kapil Porwal <kapilporwal@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Derek Huang <derekhuang@google.com>
Reviewed-by: Subrata Banik <subratabanik@google.com>
Reviewed-by: David Wu <david_wu@quanta.corp-partner.google.com>

src/mainboard/google/brya/variants/dirks/overridetree.cb

@@ -233,6 +233,7 @@ chip soc/intel/alderlake
 				register "customized_leds" = "0x05af"
 				register "wake" = "GPE0_DW2_14"	# GPP_F14
 				register "device_index" = "0"
+				register "add_acpi_dma_property" = "true"
 				device pci 00.0 on end
 			end
 		end # RTL8111H Ethernet NIC