mips: pci-lantiq: Fix check for valid gpio

This patch fixes two checks for valid gpio number, formerly (wrongly)
considering zero as invalid, now using gpio_is_valid().
Signed-off-by: Roland Stigge <stigge@antcom.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

arch/mips/pci/pci-lantiq.c

@@ -129,7 +129,7 @@ static int __devinit ltq_pci_startup(struct platform_device *pdev)
 
 	/* setup reset gpio used by pci */
 	reset_gpio = of_get_named_gpio(node, "gpio-reset", 0);
-	if (reset_gpio > 0)
+	if (gpio_is_valid(reset_gpio))
 		devm_gpio_request(&pdev->dev, reset_gpio, "pci-reset");
 
 	/* enable auto-switching between PCI and EBU */
@@ -192,7 +192,7 @@ static int __devinit ltq_pci_startup(struct platform_device *pdev)
 	ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_IEN) | 0x10, LTQ_EBU_PCC_IEN);
 
 	/* toggle reset pin */
-	if (reset_gpio > 0) {
+	if (gpio_is_valid(reset_gpio)) {
 		__gpio_set_value(reset_gpio, 0);
 		wmb();
 		mdelay(1);