As of commit 
09a5df6c444c ("drm/amd/display: Fix multi-display support
for idle opt workqueue"), vblank_lock is no longer being used. So, don't
init it in amdgpu_dm_init() and remove it from struct
amdgpu_display_manager.
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
 
        mutex_init(&adev->dm.dc_lock);
        mutex_init(&adev->dm.audio_lock);
-       spin_lock_init(&adev->dm.vblank_lock);
 
        if(amdgpu_dm_irq_init(adev)) {
                DRM_ERROR("amdgpu: failed to initialize DM IRQ support.\n");
 
         */
        struct mutex audio_lock;
 
-       /**
-        * @vblank_lock:
-        *
-        * Guards access to deferred vblank work state.
-        */
-       spinlock_t vblank_lock;
-
        /**
         * @audio_component:
         *