arm64: dts: allwinner: a64: Add device node for Mali-400 GPU

Add support for Allwinner A64 has Mali-400MP2.

All interrupt lines are mentioned in the manual so used the same.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>