iwlwifi: mvm: Do not declare support for ACK Enabled Aggregation

As this was not supposed to be enabled to begin with.

Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/iwlwifi.20200417100405.53dbc3c6c36b.Idfe118546b92cc31548b2211472a5303c7de5909@changeid