pinctrl: nomadik: Drop support for latent IRQ

The latent IRQs are IRQs that have occurred when the system
was down in deep sleep and the GPIO block was powered off.
The PRCMU (power reset and control unit) knows which GPIO
line offset fired an IRQ to wake the system up (if so
desired) and this second IRQ was used to replay the action
when the system came back online after suspend().

This is now known to be the wrong approach to solve this
problem: in a patch series Lina Iyer has suggested to
instead make it possible to model the IRQs as hierarchical
with double parents.

Also the current device trees do not contain the right
information to make this code work, the latent IRQ is not
specified nowadays giving noise like this in the console:

[    0.612168] gpio 8012e000.gpio: IRQ index 1 not found
[    0.622523] gpio 8012e080.gpio: IRQ index 1 not found

Let's delete the latent IRQ code and reimplement it properly
when we need it.

Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Lina Iyer <ilina@codeaurora.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20191014111154.9731-1-linus.walleij@linaro.org