ARM: sun8i: a83t: Replace underscores with hyphens in pinmux node names

We should use hyphens and not underscores in device node names.

Replace the ones that were just added.

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