drm/amd/display: Clear HDMI HPD pending work only if it is enabled

[Why&How]
On amdgpu_dm_connector_destroy(), the driver attempts to cancel pending
HDMI HPD work without checking if the HDMI HPD is enabled.

Added a check that it is enabled before clearing it.

Fixes: 6a681cd90345 ("drm/amd/display: Add an hdmi_hpd_debounce_delay_ms module")
Signed-off-by: Ivan Lipski <[e-mail]>
Reviewed-by: Mario Limonciello (AMD) <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>
(cherry picked from commit 17b2c526fd8026d8e0f4c0e7f94fc517e3901589)

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

···
 		drm_dp_mst_topology_mgr_destroy(&aconnector->mst_mgr);
 
 	/* Cancel and flush any pending HDMI HPD debounce work */
-	cancel_delayed_work_sync(&aconnector->hdmi_hpd_debounce_work);
-	if (aconnector->hdmi_prev_sink) {
-		dc_sink_release(aconnector->hdmi_prev_sink);
-		aconnector->hdmi_prev_sink = NULL;
+	if (aconnector->hdmi_hpd_debounce_delay_ms) {
+		cancel_delayed_work_sync(&aconnector->hdmi_hpd_debounce_work);
+		if (aconnector->hdmi_prev_sink) {
+			dc_sink_release(aconnector->hdmi_prev_sink);
+			aconnector->hdmi_prev_sink = NULL;
+		}
 	}
 
 	if (aconnector->bl_idx != -1) {