gpio: exar: Allocate resources on behalf of the platform device

Do not allocate resources on behalf of the parent device but on our own.
Otherwise, cleanup does not properly work if gpio-exar is removed but
not the parent device.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>