ARM: dts: am57xx-beagle-x15: use palmas-usb for USB2

The VBUS line of USB2 is connected to VBUS detect logic on
the PMIC. Use the palmas-usb driver to report VBUS events
to the USB driver.

As the palmas-usb driver supports GPIO based ID reporting
provide the GPIO for ID pin as well.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>