pinctrl: Add new compatible string to GPIO controller driver

This compatible string should be used for all new iproc based future
SoCs having the same GPIO controller hardware.
Signed-off-by: Pramod Kumar <pramodku@broadcom.com>
Reviewed-by: Ray Jui <rjui@broadcom.com>
Reviewed-by: Scott Branden <sbranden@broadcom.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/bcm/pinctrl-cygnus-gpio.c

@@ -645,6 +645,7 @@ static const struct of_device_id cygnus_gpio_of_match[] = {
 	{ .compatible = "brcm,cygnus-ccm-gpio" },
 	{ .compatible = "brcm,cygnus-asiu-gpio" },
 	{ .compatible = "brcm,cygnus-crmu-gpio" },
+	{ .compatible = "brcm,iproc-gpio" },
 	{ }
 };