drm/msm/a6xx: Remove an unused struct member

The HFI tasklet was removed in df0dff13 ("drm/msm/a6xx: Poll for HFI
responses") but the tasklet_struct was accidentally left behind.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/adreno/a6xx_gmu.h

@@ -75,7 +75,6 @@ struct a6xx_gmu {
 
 	struct a6xx_hfi_queue queues[2];
 
-	struct tasklet_struct hfi_tasklet;
 	bool hung;
 };