change default DMA block transfer size to 16 to improve bandwidth

software/common/validation/dma_tests.c

@@ -296,7 +296,8 @@ void dma_memory_copy (unsigned int src, unsigned int dest, unsigned int size, un
                                   (size << 24) |  /* src_size */
                                   (size << 21) |  /* dst_prot_ctrl - HPROT[3:1] */
                                   (size << 18) |  /* src_prot_ctrl - HPROT[3:1] */
-                                  (0    << 14) |  /* R_power */
+//                                  (0    << 14) |  /* R_power */
+                                  (4    << 14) |  /* R_power for 16-word block transfer*/
                                   ((num-1)<< 4) | /* n_minus_1 */
                                   (0    <<  3) |  /* next_useburst */
                                   (2    <<  0) ;  /* cycle_ctrl - auto */