v2: 
https://lore.kernel.org/linux-gpio/20210127104617.1173-1-nikita.shubin@maquefel.me/

v3:
https://lore.kernel.org/linux-gpio/20210128122123.25341-1-nikita.shubin@maquefel.me/

v3->v4 changes

[PATCH v4 1/7] gpio: ep93xx: fix BUG_ON port F usage
As suggested Alexander and Andy, drop confusing index conversion and embed 
all necessary IRQ data into struct ep93xx_gpio_irq_chip, this keeps indexes 
consistent and simplifies access.