[RFKILL]: Remove IRDA

As Dmitry pointed out earlier, rfkill-input.c
doesn't support irda because there are no users
and we shouldn't add unrequired KEY_ defines.

However, RFKILL_TYPE_IRDA was defined in the
rfkill.h header file and would confuse people
about whether it is implemented or not.

This patch removes IRDA support completely,
so it can be added whenever a driver wants the
feature.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>