Hi Graeme and Masahisa,
I updated the TF-A binaries in edk2-non-osi (with Masahisa's fix) and pushed to the following branch: http://git.linaro.org/people/tanmay.jagdale/edk2-non-osi.git/commit/?id=aa13...
I have tested this by booting on Qemu SBSA and verified that the device tree error is not showing up.
Can you please review the patch if it is okay ? If okay then I'll send it out the edk2-non-osi mailing list.
With Regards, Tanmay