gpiolib: don't use GPIO global numbers in debugfs output

One of the users of global GPIO numbers in the kernel are the debugfs
callbacks in GPIO drivers. Before converting any custom .dbg_show()
callbacks in individual modules, let's first make GPIO core stop using
GPIO base in debugfs output. Use hardware offsets instead.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20250707141313.73169-1-brgl@bgdev.pl


Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>