mb/google/brya: Enable UntrustedDevice wifi property for brask & brya

The CNVi Wifi controller is considered an untrusted device for ChromeOS,
therefore enable the new UntrustedDevice property for the cnvi_wifi
device on all brya & brask boards.

BUG=b:215424986
TEST=dump SSDT on google/redrix, verify it contains the expected
UntrustedDevice property

Change-Id: Ieff6eea0865125a7c0f626e1981dda1c9532ebb1
Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/61385
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Subrata Banik <subratabanik@google.com>

src/mainboard/google/brya/variants/baseboard/brask/devicetree.cb

@@ -117,6 +117,7 @@ chip soc/intel/alderlake
 		device ref cnvi_wifi on
 			chip drivers/wifi/generic
 				register "wake" = "GPE0_PME_B0"
+				register "is_untrusted" = "true"
 				device generic 0 on end
 			end
 		end

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

@@ -143,6 +143,7 @@ chip soc/intel/alderlake
 		device ref cnvi_wifi on
 			chip drivers/wifi/generic
 				register "wake" = "GPE0_PME_B0"
+				register "is_untrusted" = "true"
 				device generic 0 on end
 			end
 		end