drm/sti: in crtc_atomic_flush, enable only planes of this crtc

crtc_atomic_flush performs some additional processing, like plane
enable at mixer level.
Enable only the planes attached to the CRTC.

Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Acked-by: Vincent Abriou <vincent.abriou@st.com>
diff --git a/drivers/gpu/drm/sti/sti_crtc.c b/drivers/gpu/drm/sti/sti_crtc.c
index 96afe68..bc1b186 100644
--- a/drivers/gpu/drm/sti/sti_crtc.c
+++ b/drivers/gpu/drm/sti/sti_crtc.c
@@ -165,6 +165,10 @@
 
 		switch (plane->status) {
 		case STI_PLANE_UPDATED:
+			/* ignore update for other CRTC */
+			if (p->state->crtc != crtc)
+				continue;
+
 			/* update planes tag as updated */
 			DRM_DEBUG_DRIVER("update plane %s\n",
 					 sti_plane_to_str(plane));