gpiolib: of: add polarity quirk for Freescale PCIe controller

Bindings for Freescale PCIe controller use a separate property called
"reset-gpio-active-high" to control polarity of its reset line, add it
to the list of quirks in gpiolib so that gpiod API can be used in the
driver.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>