wifi: iwlwifi: mld: remove support of roc cmd version 5

The last FW API that supports version 5 is 97. Since this API is no
longer supported on any device that loads iwlmld, we can remove support
of it.

Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250909061931.e53bd8553360.I6978c216b52b818b879d076a85c5f9edafcf2e99@changeid