Allwinner SoCs typically have a Mentor Graphics Inventra MUSB dual role
controller for USB OTG.

Now that the issue with MUSB and USB gadget registration order has been
resolved, we can enable this driver in dual role mode. This requires the
NOP USB transceiver driver, which is also enabled.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>