Stable backport request for linux-4.4.y

[chenxb_99091]

From: Xuebing Chen <chenxb_99091@xxxxxxx>

In linux-4.4.y,the <include/drm/drm_crtc.h> provides drm_for_each_plane_mask macro 
and plane_mask is defined as bitmask of plane indices, such as
1 << drm_plane_index(plane). There is an error setting of plane_mask
in pan_display_atomic() function.

Please backport the following patch to the 4.4.y kernel stable tree:
commit 7118fd9bd975a9f3093239d4c0f4e15356b57fab 
("drm/fb-helper: Use proper plane mask for fb cleanup")
The above patch fixes error setting of plane_mask in pan_display_atomic() function.
    
Cc: stable@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Xuebing Chen <chenxb_99091@xxxxxxx>