gpio: zevio: Add missed label initialisation

Initialise the GPIO chip label correctly as it was done by
of_mm_gpiochip_add_data() before the below mentioned change.

Fixes: cf8f4462e5fa ("gpio: zevio: drop of_gpio.h header")
Signed-off-by: Andy Shevchenko <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Bartosz Golaszewski <[e-mail]>

drivers/gpio/gpio-zevio.c

···
 #include <linux/io.h>
 #include <linux/mod_devicetable.h>
 #include <linux/platform_device.h>
+#include <linux/property.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 
···
 /* Initialization */
 static int zevio_gpio_probe(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
 	struct zevio_gpio *controller;
 	int status, i;
 
···
 	/* Copy our reference */
 	controller->chip = zevio_gpio_chip;
 	controller->chip.parent = &pdev->dev;
+
+	controller->chip.label = devm_kasprintf(dev, GFP_KERNEL, "%pfw", dev_fwnode(dev));
+	if (!controller->chip.label)
+		return -ENOMEM;
 
 	controller->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(controller->regs))