drm/amd/display: remove faulty assert

Signed-off-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c

@@ -1776,7 +1776,6 @@ bool perform_link_training_with_retries(
 		link_enc = stream->link_enc;
 	else
 		link_enc = link->link_enc;
-	ASSERT(link_enc);
 
 	/* We need to do this before the link training to ensure the idle pattern in SST
 	 * mode will be sent right after the link training