arm64: dts: allwinner: h6: orangepi: Add device nodes for LEDs

The Orange Pi Lite 2 and Orange Pi One Plus both have two LEDs, one red
and one green. These are driven directly by GPIO lines in an active high
arrangement. The red LED is labeled "power", so it is set to be on by
default.

Note that the default drive current for the GPIO lines makes the LEDs
very bright.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>