gpio: exar: remove unneeded platform_set_drvdata() call

The platform_set_drvdata() was needed when the driver had an explicit
remove function.
That function got removed a while back, so we don't need to keep a pointer
(on 'dev->driver_data') for the private data of the driver anymore.

Reviewed-by: Alexandru Ardelean <[e-mail]>
Signed-off-by: Andrei Coardos <[e-mail]>
Reviewed-by: Andy Shevchenko <[e-mail]>
Signed-off-by: Bartosz Golaszewski <[e-mail]>

drivers/gpio/gpio-exar.c

···
 	if (ret)
 		return ret;
 
-	platform_set_drvdata(pdev, exar_gpio);
-
 	return 0;
 }