To address the ABI compatibility issue between the kernel and DTS caused by
this change, handle the compatible string 'qcom,qcs404-evb-4000' in the
code, as it is the only legacy board that mistakenly uses the 'rgmii'
phy-mode.

Are you saying every other board DT got this correct? How do you know
that? Was this SoC never shipped to anybody, so the only possible
board is the QCOM RDK which never left the lab?

I doubt this is true, so you are probably breaking out of tree
boards. We care less about out of tree boards, but we also don't
needlessly break them.

	Andrew