gpio: generic: Add label to platform data

When registering more than one platform device, it is
useful to set the gpio chip label in the platform data.

Signed-off-by: Pawel Moll <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>

drivers/gpio/gpio-generic.c

···
 		return err;
 
 	if (pdata) {
+		if (pdata->label)
+			bgc->gc.label = pdata->label;
 		bgc->gc.base = pdata->base;
 		if (pdata->ngpio > 0)
 			bgc->gc.ngpio = pdata->ngpio;

include/linux/basic_mmio_gpio.h

···
 #include <linux/spinlock_types.h>
 
 struct bgpio_pdata {
+	const char *label;
 	int base;
 	int ngpio;
 };