ARM: sun8i: a83t: Rename pinmux setting names

The pinmux setting nodes all have an address element in their node
names, however the pinctrl node does not have #address-cells.

Rename the existing pinmux setting nodes and labels in sun8i-a83t.dtsi,
dropping identifiers for functions that only have one possible setting,
and using the pingroup name if the function is identically available on
different pingroups.

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