soc: ti: add Keystone Navigator DMA support

Hello Santosh Shilimkar,

The patch 88139ed03058: "soc: ti: add Keystone Navigator DMA support" from Mar 30, 2014, leads to the following static checker warning:

	drivers/soc/ti/knav_dma.c:402 of_channel_match_helper()
	warn: unsigned 'args.args[0]' is never less than zero.

drivers/soc/ti/knav_dma.c
378 static int of_channel_match_helper(struct device_node *np, const char *name,
379 const char **dma_instance)

   380  {
   381          struct of_phandle_args args;
   382          struct device_node *dma_node;
   383          int index;
   384  
   385          dma_node = of_parse_phandle(np, "ti,navigator-dmas", 0);
   386          if (!dma_node)
   387                  return -ENODEV;
   388  
   389          *dma_instance = dma_node->name;
   390          index = of_property_match_string(np, "ti,navigator-dma-names", name);
   391          if (index < 0) {
   392                  dev_err(kdev->dev, "No 'ti,navigator-dma-names' propery\n");
   393                  return -ENODEV;
   394          }
   395  
   396          if (of_parse_phandle_with_fixed_args(np, "ti,navigator-dmas",
   397                                          1, index, &args)) {
   398                  dev_err(kdev->dev, "Missing the pahndle args name %s\n", name);
   399                  return -ENODEV;
   400          }
   401  
   402          if (args.args[0] < 0) {
                    ^^^^^^^^^^^^^^^^

I don't know what was intended here.