gpio: ep93xx: Fix wrong irq numbers in port F

Port F IRQ's should be statically mapped to EP93XX_GPIO_F_IRQ_BASE.

So we need to specify girq->first otherwise:

"If device tree is used, then first_irq will be 0 and
IRQ's get mapped dynamically on the fly"

And that's not the thing we want.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Signed-off-by: Nikita Shubin <nikita.shubin@maquefel.me>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>