ARM: sun8i: r40: add 5V regulator for Banana Pi M2 Ultra

ARM: sun8i: r40: add 5V regulator for Banana Pi M2 Ultra

On newer revisions of the Banana Pi M2 Ultra boards, the 5V power output
(used by HDMI, SATA and USB) is controller via a GPIO.

Add the regulator node for it.

Older revisions just have the 5V power output always on, and the GPIO is
reserved on these boards. So it won't affect the older revisions.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>