In preparation for adding a second interrupt to service RTC
interrupts, the existing interrupt is renamed from the generic
'irq' to 'wake_irq' to more clearly convey its role.
It is also converted to an unsigned int.
Finally, the driver message that outputs the IRQ number when
registered is removed since devm_rtc_register_device() already
provides a report of registration and the interrupts can be
found in /proc/interrupts.
Signed-off-by: Doug Berger <opendmb@xxxxxxxxx>