gpio: export of_pinctrl_get to modules

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lore.kernel.org/r/20200401151904.6948af20@canb.auug.org.au


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