drm/sun4i: Fix layer zpos change/atomic modesetting

Identical configurations of planes can lead to different (and wrong)
layer -> pipe routing at HW level, depending on the order of atomic
plane changes.

For example:

- Layer 1 is configured to zpos 0 and thus uses pipe 0. No other layer
  is enabled. This is a typical situation at boot.

- When a compositor takes over and layer 3 is enabled,
  sun8i_ui_layer_enable() will get called with old_zpos=0 zpos=1, which
  will lead to incorrect disabling of pipe 0 and enabling of pipe 1.

What happens is that sun8i_ui_layer_enable() function may disable
blender pipes even if it is no longer assigned to its layer.

To correct this, move the routing setup out of individual plane's
atomic_update into crtc's atomic_update, where it can be calculated
and updated all at once.

Remove the atomic_disable callback because it is no longer needed.

Signed-off-by: Ondrej Jirman <megi@xff.cz>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20240224150604.3855534-4-megi@xff.cz


Signed-off-by: Maxime Ripard <mripard@kernel.org>