drm/msm: strip out msm_fence_cb

Remnants of pre-dma_fence fencing which got left behind by mistake.
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/msm_drv.h

@@ -51,7 +51,6 @@ struct msm_rd_state;
 struct msm_perf_state;
 struct msm_gem_submit;
 struct msm_fence_context;
-struct msm_fence_cb;
 struct msm_gem_address_space;
 struct msm_gem_vma;
 

drivers/gpu/drm/msm/msm_fence.h

@@ -37,8 +37,6 @@ void msm_fence_context_free(struct msm_fence_context *fctx);
 
 int msm_wait_fence(struct msm_fence_context *fctx, uint32_t fence,
 		ktime_t *timeout, bool interruptible);
-int msm_queue_fence_cb(struct msm_fence_context *fctx,
-		struct msm_fence_cb *cb, uint32_t fence);
 void msm_update_fence(struct msm_fence_context *fctx, uint32_t fence);
 
 struct dma_fence * msm_fence_alloc(struct msm_fence_context *fctx);