gpio: exar: use devm action for freeing the IDA and drop remove()

We can simplify the error path in probe() and drop remove() entirely if
we provide a devm action for freeing the device ID.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>