iwlwifi: fw: fix notification wait locking

Since we now call iwl_notification_wait_notify() from the
NAPI poll in soft-IRQ, we get a (valid) lockdep complaint
that we could get a deadlock by taking the spinlock from
sleeping context and then getting the soft-IRQ that also
tries to take it (in NAPI polling).

Fix this by disabling soft-IRQs for this lock.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Fixes: 25edc8f2

 ("iwlwifi: pcie: properly implement NAPI")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/iwlwifi.20210326125611.c3b2e3d6b58b.Ic56f351d04674df70567bab0269cba91bdbc853c@changeid