drm/armada: move write to dma_ctrl0 to armada_drm_crtc_plane_disable()

Move the write to clear the DMA enable bit, and augment it with clearing
the graphics enable bit for the primary plane.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/gpu/drm/armada/armada_overlay.c

@@ -275,7 +275,6 @@ static int armada_ovl_plane_disable(struct drm_plane *plane)
 
 	spin_lock_irq(&dcrtc->irq_lock);
 	armada_drm_vbl_event_remove(dcrtc, &dplane->vbl.update);
-	armada_updatel(0, CFG_DMA_ENA, dcrtc->base + LCD_SPU_DMA_CTRL0);
 	dplane->ctrl0 = 0;
 	spin_unlock_irq(&dcrtc->irq_lock);