drm/amd/display: Remove DISPCLK dentist programming for dcn32

[WHY?]
For dcn32, SMU handles DISPCLK dentist programming.

[HOW?]
Only use calls to SMU to set DISPCLK.

Tested-by: Daniel Wheeler <Daniel.Wheeler@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Dillon Varone <Dillon.Varone@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>