iwlwifi: mvm: fix 22000 series driver NMI

iwlwifi: mvm: fix 22000 series driver NMI

For triggering an NMI in the firmware, we should only set BIT(24)
in the corresponding register, not the entire mask that's usable
by the driver.

This currently doesn't matter because the firmware only enables
BIT(24), but we'll start using BIT(25) for other purposes with an
upcoming API change.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20201209231352.2f982365d085.Id09daabfd331ba9e120abcbbedd2ad6448902ed0@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>