wifi: iwlwifi: mld: don't check the cipher on resume

wifi: iwlwifi: mld: don't check the cipher on resume

On resume, we are iterating all the keys in order to update the PN.
Currently we check the cipher of the key we are currently iterating on
to decide whether the key is PTK, GTK, IGTK or BIGTK.
But we can find the type of the key by the keyidx, and we anyway have to
check the keyidx, so just remove the cipher switch case and check only
the keyidx instead

Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250826184046.8c4f9c30242c.Ie34c200f321aae60771476fa9907c333a8a99747@changeid