disable usage of 8x8 for resolution below 360p

need further investigation on some odd behavior on one  youtube clip

Change-Id: Iec477986a86b54ef26df2ef69d2f9484e2d1a043

vp8/encoder/ratectrl.c

@@ -269,8 +269,8 @@ void vp8_setup_key_frame(VP8_COMP *cpi)
 void vp8_setup_inter_frame(VP8_COMP *cpi)
 {
 #if CONFIG_T8X8
-    if(cpi->common.Width * cpi->common.Height > 640*360
-        ||cpi->this_frame_target < 7 * cpi->common.MBs)
+    if(cpi->common.Width * cpi->common.Height > 640*360)
+        //||cpi->this_frame_target < 7 * cpi->common.MBs)
         cpi->common.txfm_mode = ALLOW_8X8;
     else
         cpi->common.txfm_mode = ONLY_4X4;