iwlwifi: add TLV for MLME offload firmware capability

The firmware now adds a new DWORD for the MLME offload's
capability even on firmware versions that don't support
it.
Add the TLV bit to avoid getting the print:
capa flags index 3 larger than supported by driver.

This fixes the bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=196195

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>