gpio: omap: Give unique labels to each GPIO bank/chip

As we need to add GPIO lookup tables to the OMAP platforms, we
need to reference each GPIO chip with a unique label. Use the GPIO
base to name each chip, "gpio-0-31", "gpio-32-63" etc.

Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Santosh Shilimkar <ssantosh@kernel.org>
Cc: Kevin Hilman <khilman@kernel.org>
Cc: linux-omap@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-omap.c

@@ -1060,6 +1060,7 @@ static int omap_gpio_chip_init(struct gpio_bank *bank, struct irq_chip *irqc)
 {
 	struct gpio_irq_chip *irq;
 	static int gpio;
+	const char *label;
 	int irq_base = 0;
 	int ret;
 
@@ -1081,7 +1082,11 @@ static int omap_gpio_chip_init(struct gpio_bank *bank, struct irq_chip *irqc)
 			bank->chip.parent = &omap_mpuio_device.dev;
 		bank->chip.base = OMAP_MPUIO(0);
 	} else {
-		bank->chip.label = "gpio";
+		label = devm_kasprintf(bank->chip.parent, GFP_KERNEL, "gpio-%d-%d",
+				       gpio, gpio + bank->width - 1);
+		if (!label)
+			return -ENOMEM;
+		bank->chip.label = label;
 		bank->chip.base = gpio;
 	}
 	bank->chip.ngpio = bank->width;