usb: gadget: udc: atmel: Don't use DT to configure end point

usb: gadget: udc: atmel: Don't use DT to configure end point

The endpoint configuration used to be stored in the device tree,
however the configuration depend on the "version" of the controller
itself.

This information is already documented by the compatible string. It
then possible to just rely on the compatible string and completely
remove the full ep configuration done in the device tree as it was
already the case for all the other USB device controller.

Acked-by: Cristian Birsan <cristian.birsan@microchip.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>