arm: omap: add support for am57xx devices

just add a few ifdefs around because this
device is very similar to dra7xxx.

Signed-off-by: Felipe Balbi <balbi@ti.com>
configs: beagle_x15: this is actually an AM57x device

just to make things a little clearer.

Signed-off-by: Felipe Balbi <balbi@ti.com>
beagle_x15: enable the USB host port

This patch enables the USB host port on the
Beagle x15 board.

Signed-off-by: Felipe Balbi <balbi@ti.com>
board: ti: beagle-x15: change name to BeagleBoard x15

Signed-off-by: Felipe Balbi <balbi@ti.com>