drivers/ioexpander: The IRQ subsystem now supports passing a void * parameter...

drivers/ioexpander:  The IRQ subsystem now supports passing a void * parameter to IRQ handlers.  Use that method to support multiple pc9555 devices, by passing a pointer to the device to the board defined irq handler.  Now the CONFIG_ for multiple PCA devices just allocates device structures dynamically instead of statically when not enabled.

The same interrupt handler is entered with the device structure parameter in all situations,
multiple or single PCA. One should still be careful if multiple PCA devices share the same IRQ.