pinctrl: mcp23s08: Check only GPIOs which have interrupts enabled

GPINTEN register contains information about GPIOs with enabled
interrupts no need to check other GPIOs for changes.

Signed-off-by: Arturas Moskvinas <arturas.moskvinas@gmail.com>
Link: https://lore.kernel.org/r/20240201141406.32484-2-arturas.moskvinas@gmail.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>