drm/amd/display: clean up set_bandwidth usage

This removes redundant set_bandwidth calls as well
as fixes a bug in post_set_address_update where dcn1
would never get to lower clocks.

Signed-off-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Reviewed-by: Nikola Cornij <Nikola.Cornij@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>