spi: clps711x: Provide label argument for devm_gpio_request

The label argument was removed by commit 98984796
spi: clps711x: Use devm_gpio_request(), add it back.
This makes it easier to know the gpio usage in /sys/kernel/debug/gpio.

Also remove unnecessary gpio_is_valid() checking, devm_gpio_request() returns
error if the requested gpio is invalid.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/spi/spi-clps711x.c

@@ -159,14 +159,10 @@ static int spi_clps711x_probe(struct platform_device *pdev)
 
 	for (i = 0; i < master->num_chipselect; i++) {
 		master->cs_gpios[i] = pdata->chipselect[i];
-		if (!gpio_is_valid(master->cs_gpios[i])) {
-			dev_err(&pdev->dev, "Invalid CS GPIO %i\n", i);
-			ret = -EINVAL;
-			goto err_out;
-		}
-		if (devm_gpio_request(&pdev->dev, master->cs_gpios[i], NULL)) {
+		ret = devm_gpio_request(&pdev->dev, master->cs_gpios[i],
+					DRIVER_NAME);
+		if (ret) {
 			dev_err(&pdev->dev, "Can't get CS GPIO %i\n", i);
-			ret = -EINVAL;
 			goto err_out;
 		}
 	}