HID: cp2112: Don't call ->to_irq() explicitly

GPIO library guarantees that ->to_irq() is always exists.
Moreover, it tending to become a nische thingy and has to
not be used in ordinary drivers. Hence, replace that by
irq_find_mapping().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230703185222.50554-6-andriy.shevchenko@linux.intel.com


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