ARM: dts: sun8i: r40: add sata node

R40 have a sata controller which is the same as A20.
This patch adds a DT node for it.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>