drm/msm/mdp5: fix incorrect parameter for msm_framebuffer_iova()

The index of ->planes[] array (3rd parameter) cannot be equal to MAX_PLANE.
This looks like a typo that is now fixed.
Signed-off-by: Stephane Viau <sviau@codeaurora.org>
Acked-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c

@@ -273,7 +273,7 @@ static void set_scanout_locked(struct drm_plane *plane,
 	mdp5_write(mdp5_kms, REG_MDP5_PIPE_SRC2_ADDR(pipe),
 			msm_framebuffer_iova(fb, mdp5_kms->id, 2));
 	mdp5_write(mdp5_kms, REG_MDP5_PIPE_SRC3_ADDR(pipe),
-			msm_framebuffer_iova(fb, mdp5_kms->id, 4));
+			msm_framebuffer_iova(fb, mdp5_kms->id, 3));
 
 	plane->fb = fb;
 }