pinctrl: iproc: Add 'get_direction' support

Add 'get_direction' support to the iProc GPIO driver.

Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>
Link: https://lore.kernel.org/r/1568178685-30738-1-git-send-email-rayagonda.kokatanur@broadcom.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>