gpio: ts4800: Remove duplicate code to handle 'ngpios' property

The gpio_generic_chip_init() handles the 'ngpios' property and
assigns the respective field in struct gpio_chip either with
the value of it, or, if not found, with the default based on
the register size. There is no need to repeat this in the driver.

Signed-off-by: Andy Shevchenko <[e-mail]>
Reviewed-by: Linus Walleij <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Bartosz Golaszewski <[e-mail]>

drivers/gpio/gpio-ts4800.c

···
 #include <linux/platform_device.h>
 #include <linux/property.h>
 
-#define DEFAULT_PIN_NUMBER      16
 #define INPUT_REG_OFFSET        0x00
 #define OUTPUT_REG_OFFSET       0x02
 #define DIRECTION_REG_OFFSET    0x04
···
 	struct gpio_generic_chip *chip;
 	void __iomem *base_addr;
 	int retval;
-	u32 ngpios;
 
 	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
 	if (!chip)
···
 	base_addr = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(base_addr))
 		return PTR_ERR(base_addr);
-
-	retval = device_property_read_u32(dev, "ngpios", &ngpios);
-	if (retval == -EINVAL)
-		ngpios = DEFAULT_PIN_NUMBER;
-	else if (retval)
-		return retval;
 
 	config = (struct gpio_generic_chip_config) {
 		.dev = dev,
···
 	if (retval)
 		return dev_err_probe(dev, retval,
 				     "failed to initialize the generic GPIO chip\n");
-
-	chip->gc.ngpio = ngpios;
 
 	return devm_gpiochip_add_data(dev, &chip->gc, NULL);
 }