gpio: samsung: adapt to changes in gpio specifier translator function declaration

Commit 15c9a0acc3f7 (of: create of_phandle_args to simplify return of phandle
parsing data) modifies the parameter list of of_xlate function pointer declaration
in gpio_chip. Adapt the gpio specifier translate function for this change.

Reported-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Tested-by: Karol Lewandowski <k.lewandowsk@samsung.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>