Remove const qualifier from AOM_QM seg matrices

This was causing visual stuido warnings when attempting to write
to seg_iqmatrix and seg_qmatrix using memcpy.

Change-Id: Idf12464c8c90c83af9c2b3ea399d739f7df3b5f9

av1/common/blockd.h

@@ -632,8 +632,8 @@ typedef struct macroblockd_plane {
   uint8_t width, height;
 
 #if CONFIG_AOM_QM
-  const qm_val_t *seg_iqmatrix[MAX_SEGMENTS][2][TX_SIZES_ALL];
-  const qm_val_t *seg_qmatrix[MAX_SEGMENTS][2][TX_SIZES_ALL];
+  qm_val_t *seg_iqmatrix[MAX_SEGMENTS][2][TX_SIZES_ALL];
+  qm_val_t *seg_qmatrix[MAX_SEGMENTS][2][TX_SIZES_ALL];
 #endif
   // encoder
   const int16_t *dequant;

av1/decoder/detokenize.c

@@ -106,7 +106,7 @@ static int decode_coefs(MACROBLOCKD *xd, PLANE_TYPE type, tran_low_t *dqcoeff,
                         dequant_val_type_nuq *dq_val,
 #else
 #if CONFIG_AOM_QM
-                        const qm_val_t *iqm[2][TX_SIZES_ALL],
+                        qm_val_t *iqm[2][TX_SIZES_ALL],
 #endif  // CONFIG_AOM_QM
 #endif  // CONFIG_NEW_QUANT
                         int ctx, const int16_t *scan, const int16_t *nb,