sh-pfc: Make GPIO support optional

When implemented as a separate IP block, GPIOs should be handled by a
separate driver. To make this possible GPIO support needs to be optional
in the sh-pfc driver.

If no GPIO data registers are supplied in the SoC information structure
skip registration of the gpiochip.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

drivers/pinctrl/sh-pfc/gpio.c

@@ -354,6 +354,9 @@ int sh_pfc_register_gpiochip(struct sh_pfc *pfc)
 	unsigned int i;
 	int ret;
 
+	if (pfc->info->data_regs == NULL)
+		return 0;
+
 	/* Register the real GPIOs chip. */
 	chip = sh_pfc_add_gpiochip(pfc, gpio_pin_setup);
 	if (IS_ERR(chip))