drm/armada: fix SRAM powerdown

Avoid powering down the overlay SRAM banks when disabling the primary
plane, thereby masking any overlay video.  This feature is supposed to
allow us to cut the bandwidth required while displaying full-frame
overlay video.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

drivers/gpu/drm/armada/armada_crtc.c

@@ -744,15 +744,14 @@ void armada_drm_crtc_plane_disable(struct armada_crtc *dcrtc,
 	if (plane->fb)
 		drm_framebuffer_put(plane->fb);
 
-	/* Power down the Y/U/V FIFOs */
-	sram_para1 = CFG_PDWN16x66 | CFG_PDWN32x66;
-
 	/* Power down most RAMs and FIFOs if this is the primary plane */
 	if (plane->type == DRM_PLANE_TYPE_PRIMARY) {
-		sram_para1 |= CFG_PDWN256x32 | CFG_PDWN256x24 | CFG_PDWN256x8 |
-			      CFG_PDWN32x32 | CFG_PDWN64x66;
+		sram_para1 = CFG_PDWN256x32 | CFG_PDWN256x24 | CFG_PDWN256x8 |
+			     CFG_PDWN32x32 | CFG_PDWN64x66;
 		dma_ctrl0_mask = CFG_GRA_ENA;
 	} else {
+		/* Power down the Y/U/V FIFOs */
+		sram_para1 = CFG_PDWN16x66 | CFG_PDWN32x66;
 		dma_ctrl0_mask = CFG_DMA_ENA;
 	}