ARM: dts: sun8i: Enable timer node for A83T

A83T timer is compatible with that of earlier SOCs.
Just add timer node to enable and re-use it.

Signed-off-by: Vishnu Patekar <vishnupatekar0510@gmail.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>