drm/amd/display: Fix 2nd DPIA encoder Assignment

[HOW & Why]
There seems to be an issue with 2nd DPIA acquiring link encoder for tiled displays.
Solution is to remove check for eng_id before we get first dynamic encoder for it
Reviewed-by: Cruise Hung <cruise.hung@amd.com>
Reviewed-by: Meenakshikumar Somasundaram <meenakshikumar.somasundaram@amd.com>
Cc: Mario Limonciello <mario.limonciello@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Acked-by: Stylon Wang <stylon.wang@amd.com>
Signed-off-by: Mustapha Ghaddar <mghaddar@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_enc_cfg.c

@@ -395,8 +395,7 @@ void link_enc_cfg_link_encs_assign(
 					stream->link->dpia_preferred_eng_id != ENGINE_ID_UNKNOWN)
 				eng_id_req = stream->link->dpia_preferred_eng_id;
 
-			if (eng_id == ENGINE_ID_UNKNOWN)
-				eng_id = find_first_avail_link_enc(stream->ctx, state, eng_id_req);
+			eng_id = find_first_avail_link_enc(stream->ctx, state, eng_id_req);
 		}
 		else
 			eng_id =  link_enc->preferred_engine;
@@ -501,7 +500,6 @@ struct dc_link *link_enc_cfg_get_link_using_link_enc(
 	if (stream)
 		link = stream->link;
 
-	// dm_output_to_console("%s: No link using DIG(%d).\n", __func__, eng_id);
 	return link;
 }