The A20 SoC has a sun4i-compatible DMA controller. Let's add a node to
represent it on the device tree.
Signed-off-by: Emilio López <emilio@elopez.com.ar>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>