wifi: iwlwifi: api: use __le16 instead of u16

Even for reserved values we shouldn't use u16, that's just
error prone. Fix this to __le16.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230601171633.29ebf70aa64e.I1263f6724e1c70ff5541f447b9744f143ee736a3@changeid


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