Separate quantizaton for U and V plane

This commit adds code to support separate regular quantization for U
and V. They currently always use same quantization parameter, hence
this commit does not change bitstream at all.

Change-Id: Ifaf43e4fd0bcd01b1483f2dacf3ac498003d5db1
diff --git a/av1/decoder/inspection.h b/av1/decoder/inspection.h
index bd9d87a..8d19fcc 100644
--- a/av1/decoder/inspection.h
+++ b/av1/decoder/inspection.h
@@ -75,7 +75,8 @@
   int tile_mi_rows;
   int tile_mi_cols;
   int16_t y_dequant[MAX_SEGMENTS][2];
-  int16_t uv_dequant[MAX_SEGMENTS][2];
+  int16_t u_dequant[MAX_SEGMENTS][2];
+  int16_t v_dequant[MAX_SEGMENTS][2];
 #if CONFIG_CDEF
 // TODO(negge): add per frame CDEF data
 #endif