HID: cp2112: Make irq_chip immutable

Since recently, the kernel is nagging about mutable irq_chips:

   "not an immutable chip, please consider fixing it!"

Drop the unneeded copy, flag it as IRQCHIP_IMMUTABLE, add the new
helper functions and call the appropriate gpiolib functions.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230703185222.50554-4-andriy.shevchenko@linux.intel.com


Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>