"usb-ohci" is another "generic" OHCI controller compatible string used by
several platforms. Add it to the generic-ohci.yaml schema and remove all
the old binding docs.

Marvell pxa-usb.txt has "usb-ohci" in the example, but actual users don't,
so drop it.
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230110-dt-usb-v3-2-5af0541fcf8c@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>