drm/amd/display: setting the DIG_MODE to the correct value.

[Why]
This patch is for fixing Navi14 HDMI display pink screen issue.

[How]
Call stream->link->link_enc->funcs->setup twice. This is setting
the DIG_MODE to the correct value after having been overridden by
the call to transmitter control.

Signed-off-by: Zhan Liu <zhan.liu@amd.com>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>