gpio: Drop explicit initialization of struct i2c_device_id::driver_data to 0

These drivers don't use the driver_data member of struct i2c_device_id,
so don't explicitly initialize this member.

This prepares putting driver_data in an anonymous union which requires
either no initialization or named designators. But it's also a nice
cleanup on its own.

Signed-off-by: Uwe Kleine-König <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Bartosz Golaszewski <[e-mail]>

drivers/gpio/gpio-fxl6408.c

···
 MODULE_DEVICE_TABLE(of, fxl6408_dt_ids);
 
 static const struct i2c_device_id fxl6408_id[] = {
-	{ "fxl6408", 0 },
+	{ "fxl6408" },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, fxl6408_id);

drivers/gpio/gpio-max7300.c

···
 }
 
 static const struct i2c_device_id max7300_id[] = {
-	{ "max7300", 0 },
+	{ "max7300" },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, max7300_id);