gpio: idio-16: Actually make use of the GPIO_IDIO_16 symbol namespace

gpio: idio-16: Actually make use of the GPIO_IDIO_16 symbol namespace

DEFAULT_SYMBOL_NAMESPACE must already be defined when <linux/export.h>
is included. So move the define above the include block.

Fixes: b9b1fc1ae119 ("gpio: idio-16: Introduce the ACCES IDIO-16 GPIO library module")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Acked-by: William Breathitt Gray <wbg@kernel.org>
Link: https://lore.kernel.org/r/20241203172631.1647792-2-u.kleine-koenig@baylibre.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>