drm/amd/display: Reprogram FMT on pipe change

[Why]
When planes are added or removed from a stream, the change
in pipe usage from dynamic MPC combine can cause a second
stream using ODM combine to pick a different pipe to combine with.

In this scenario, a different OPP is connected to the ODM without
programming its FMT.

[How]
Reprogram the FMT in dcn20_program_pipe whenever a pipe is
newly enabled, or when its opp changes.

Signed-off-by: Julian Parkin <julian.parkin@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>