usb: chipidea: set usb otg capabilities

Init and update otg capabilities by DT, set gadget's otg capabilities
accordingly.

Acked-by: Peter Chen <peter.chen@freescale.com>
Reviewed-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Li Jun <jun.li@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>