Convert the RMI driver to use the standard mechanism for
distributing IRQs to the various functions.

Tested on:
* S7300 (F11, F34, F54)
* S7817 (F12, F34, F54)
Signed-off-by: Nick Dyer <nick@shmanahar.org>
Acked-by: Christopher Heiny <cheiny@synaptics.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>