drm/amd/display: dpia should avoid encoder used by dp2

[WHY]
In current HPO DP2 implementation, driver would enable/disable DIG
encoder when configuring HPO DP2. Therefore, usb4 dp tunnelling should
not use the DIG encoder if the corresponded phy is used by a HPO DP2
stream.

[HOW]
A DP2 stream is treated as a dig stream.

Reviewed-by: Meenakshikumar Somasundaram <meenakshikumar.somasundaram@amd.com>
Signed-off-by: Peichen Huang <PeiChen.Huang@amd.com>
Signed-off-by: Roman Li <roman.li@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Author: Peichen Huang

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

@@ -44,20 +44,8 @@ static bool is_dig_link_enc_stream(struct dc_stream_state *stream)
 			 * yet match.
 			 */
 			if (link_enc && ((uint32_t)stream->link->connector_signal & link_enc->output_signals)) {
-				if (dc_is_dp_signal(stream->signal)) {
-					/* DIGs do not support DP2.0 streams with 128b/132b encoding. */
-					struct dc_link_settings link_settings = {0};
-
-					stream->ctx->dc->link_srv->dp_decide_link_settings(stream, &link_settings);
-					if ((link_settings.link_rate >= LINK_RATE_LOW) &&
-							link_settings.link_rate <= LINK_RATE_HIGH3) {
-						is_dig_stream = true;
-						break;
-					}
-				} else {
-					is_dig_stream = true;
-					break;
-				}
+				is_dig_stream = true;
+				break;
 			}
 		}
 	}