rt2x00: Add suspend/resume handlers to rt2x00rfkill

Add suspend/resume handlers to rt2x00rfkill to have it stop
the input-polldev and prevent it from calling rt2x00 during
suspend period. This could lead to a NULL pointer fault when
rt2x00 suspended, but polldev send a request, because
the csr_addr is NULL.

Also don't let the rfkill allocation/registration block
the initialization of the entire device. Just print a warning
and continue as if nothing happened.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>