dt-bindings: usb: Convert OMAP OHCI/EHCI bindings to schema

The OMAP OHCI and EHCI USB host bindings follow the generic binding, so
add the compatibles and remove the old txt binding docs.

The examples in omap-usb-host.txt don't match actual users, so update
them dropping the fallback compatible.

Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230110-dt-usb-v3-3-5af0541fcf8c@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>