drm/amd/display: Add Z8 watermarks for DML2 bbox overrides

[Why]
We can override SR watermarks but not Z8 ones.

[How]
Add new parameters for Z8 matching the SR ones and feed them into the
states.

These also weren't being applied to every state, so make sure that
we loop over and update all SOC states if given an override.

Reviewed-by: Jun Lei <jun.lei@amd.com>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>