mem spibaud uses NG. And a simplification of tuning

client/cmdflashmem.c

@@ -117,7 +117,7 @@ static int CmdFlashmemSpiBaudrate(const char *Cmd) {
         usage_flashmem_spibaud();
         return PM3_EINVARG;
     }
-    SendCommandMIX(CMD_FLASHMEM_SET_SPIBAUDRATE, baudrate, 0, 0, NULL, 0);
+    SendCommandNG(CMD_FLASHMEM_SET_SPIBAUDRATE, (uint8_t*)&baudrate, sizeof(uint32_t));
     return PM3_SUCCESS;
 }