drm/amd/display: Remove mst_hotplug_work

[Why]
The work struct's schedule call was removed a while ago, making this
useless.

[How]
Remove it.

Signed-off-by: Leo Li <sunpeng.li@amd.com>
Reviewed-by: David Francis <David.Francis@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -338,14 +338,6 @@ static int dm_set_powergating_state(void *handle,
 /* Prototypes of private functions */
 static int dm_early_init(void* handle);
 
-static void hotplug_notify_work_func(struct work_struct *work)
-{
-	struct amdgpu_display_manager *dm = container_of(work, struct amdgpu_display_manager, mst_hotplug_work);
-	struct drm_device *dev = dm->ddev;
-
-	drm_kms_helper_hotplug_event(dev);
-}
-
 /* Allocate memory for FBC compressed data  */
 static void amdgpu_dm_fbc_init(struct drm_connector *connector)
 {
@@ -447,8 +439,6 @@ static int amdgpu_dm_init(struct amdgpu_device *adev)
 		goto error;
 	}
 
-	INIT_WORK(&adev->dm.mst_hotplug_work, hotplug_notify_work_func);
-
 	adev->dm.freesync_module = mod_freesync_create(adev->dm.dc);
 	if (!adev->dm.freesync_module) {
 		DRM_ERROR(

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

@@ -108,8 +108,6 @@ struct amdgpu_display_manager {
 
 	const struct dc_link *backlight_link;
 
-	struct work_struct mst_hotplug_work;
-
 	struct mod_freesync *freesync_module;
 
 	/**