gpio: ge: Utilise temporary variable for struct device

We have a temporary variable to keep pointer to struct device.
Utilise it inside the ->probe() implementation.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>