gpio: davinci: implement .get_direction()

gpio: davinci: implement .get_direction()

It's strongly recommended for GPIO drivers to always implement the
.get_direction() callback - even for fixed-direction controllers.

GPIO core will even emit a warning if the callback is missing, when
users try to read the direction of a pin.

Implement .get_direction() for gpio-davinci.

Reported-by: Michael Walle <mwalle@kernel.org>
Closes: https://lore.kernel.org/all/DFJAFK3DTBOZ.3G2P3A5IH34GF@kernel.org/
Reviewed-by: Linus Walleij <linusw@kernel.org>
Fixes: a060b8c511ab ("gpiolib: implement low-level, shared GPIO support")
Tested-by: Michael Walle <mwalle@kernel.org> # on sa67
Link: https://lore.kernel.org/r/20260109130832.27326-1-bartosz.golaszewski@oss.qualcomm.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>