drm: sun4i: de33: mixer: add mixer configuration for the H616

drm: sun4i: de33: mixer: add mixer configuration for the H616

The H616 (and related SoC packages sharing the same die) carry the new
DE33 display engine.

Add the mixer configuration and a compatible string for the H616 to the
mixer.

Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Ryan Walklin <ryan@testtoast.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Link: https://lore.kernel.org/r/20250528092431.28825-9-ryan@testtoast.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>