gpiolib: of: do not ignore requested index when applying quirks

We should not ignore index passed into of_find_gpio() when handling
quirks. While in practice this change will not have any effect, it
will allow consolidate quirk handling.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>