Add a custom xrx200 ethernet phy compatible to load the firmware matching
the vr9 revision without specifing an expected revision.
We have quite a few boards in the tree were later produced ones are using
a more recent vr9. It is impossible to distinguish which revision of the
vr9 is used without opening the case and removing a heatsink for some of
them.
Signed-off-by: Mathias Kresin <dev@kresin.me>
