drivers: gpio: sifive: support port_get_direction
drivers: gpio: sifive: support port_get_direction

Support querying the direction of GPIO.

Signed-off-by: Christopher Friedt <b335fc22cf1358c7e834a5788f93b9f24396b889@fb.com>

finikorg/zephyr,finikorg/zephyr,galak/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr