[U-Boot] [BUG] x86: Could not get phandle node for /gpios@0:num-gpios(cell 0)

When running the Travis test suite for master I see warnings

arch/sandbox/dts/sandbox.dtb: Warning (gpios_property): Could not get phandle node for /gpios@0:num-gpios(cell 0) (https://travis-ci.org/xypron2/u-boot/jobs/329755777)

The warning is created by check_gpios_property() in scripts/dtc/checks.c.

This seems to be cause by the following patch: 999a78d5cf00dfb8cd8342454933ea492e955377 ("scripts/dtc: Update to upstream version v1.4.5-3-gb1a60033c110")

I guess that the dts is ok and the test is incorrect. Could you, please, have look.

Best regards

Heinrich