drm/amd/display: do not disable an invalid irq source in hdp finish

[why]
Observing error log about trying to disable non-implemented irq source
when user unload the driver.

[how]
Check and filter the invalid irq source before disabling it.

Reviewed-by: Qingqing (Lillian) Zhuo <[e-mail]>
Acked-by: Stylon Wang <[e-mail]>
Signed-off-by: Alan Liu <[e-mail]>
Tested-by: Daniel Wheeler <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

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

···
 				to_amdgpu_dm_connector(connector);
 		const struct dc_link *dc_link = amdgpu_dm_connector->dc_link;
 
-		dc_interrupt_set(adev->dm.dc, dc_link->irq_source_hpd, false);
+		if (DC_IRQ_SOURCE_INVALID != dc_link->irq_source_hpd) {
+			dc_interrupt_set(adev->dm.dc,
+					dc_link->irq_source_hpd,
+					false);
+		}
 
 		if (DC_IRQ_SOURCE_INVALID != dc_link->irq_source_hpd_rx) {
 			dc_interrupt_set(adev->dm.dc,