iwlwifi: extend notification wait

Sometimes, for example when we ask the uCode
for calibration, we wait for the "complete"
response while we also need the results that
are sent in other, interim, notifications.

Currently we handle this by installing an RX
handler globally, but that isn't needed as
this is the only time we want to use these
notifications.

So in order to be able to simplify at least
future code that does the same, extend the
notification wait framework to allow you to
wait for multiple commands and decide based
on the command whether the wait finished.

While at it, also fix a race that can then
become relevant -- if the wait function has
returned true once it shouldn't be called
again, today this can happen due to races
between the triggering and the wakeup.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>