gpio: TODO: track the removal of regulator-related workarounds

gpio: TODO: track the removal of regulator-related workarounds

The GPIOD_FLAGS_BIT_NONEXCLUSIVE flag and devm_gpiod_unhinge() function
should be replaced with a better solution. The pwrseq subsystem is a good
candidate. GPIOs themselves should remain a unique resource. Add a task
for tracking the removal of these deprecated symbols.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20250401-gpio-todo-remove-nonexclusive-v2-4-7c1380797b0d@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>