gpio: cdev: don't report GPIOs requested as interrupts as used

GPIOs used as shared irqs can still be requested by user-space (or
kernel drivers for that matter) yet we report them as used over the
chardev ABI. Drop the test for FLAG_USED_AS_IRQ from
gpio_desc_to_lineinfo().

Reviewed-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20241031200842.22712-1-brgl@bgdev.pl


Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>