On the A13 Q8 tablets, the PMIC's USB power supply (VBUS) is connected
to the external OTG port. This can be used to provide power and OTG VBUS
sensing.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>