gpio: devres: Switch to EXPORT_SYMBOL_GPL()

Change all exported symbols for managed GPIO functions from
EXPORT_SYMBOL() to EXPORT_SYMBOL_GPL(), like is used for their
non-managed counterparts.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20190906084539.21838-5-geert+renesas@glider.be


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