gpio-sta2x11: Convert to use devm_ioremap_resource

Commit 75096579 ("lib: devres: Introduce devm_ioremap_resource()")
introduced devm_ioremap_resource() and deprecated the use of
devm_request_and_ioremap().
Signed-off-by: NTushar Behera <tushar.behera@linaro.org>
CC: linux-gpio@vger.kernel.org
CC: Grant Likely <grant.likely@linaro.org>
CC: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-sta2x11.c

@@ -374,7 +374,9 @@ static int gsta_probe(struct platform_device *dev)
 	if (!chip)
 		return -ENOMEM;
 	chip->dev = &dev->dev;
-	chip->reg_base = devm_request_and_ioremap(&dev->dev, res);
+	chip->reg_base = devm_ioremap_resource(&dev->dev, res);
+	if (IS_ERR(chip->reg_base))
+		return PTR_ERR(chip->reg_base);
 
 	for (i = 0; i < GSTA_NR_BLOCKS; i++) {
 		chip->regs[i] = chip->reg_base + i * 4096;