iwlwifi: mvm: reset seq num after restart

After a FW reset on A000 NICs, the driver doesn't
set the seq number when re-allocating the queues.
This in turn leads to a mismatch between the seq
number the driver thinks each frame has, and the
actual seq num given by the HW.

This especially causes issues with aggregations,
since the driver could be waiting to start an
aggregation and queue traffic from the mac80211
until then, when actually it shouldn't be waiting.

Fixes: 310181ec ("iwlwifi: move to TVQM mode")
Signed-off-by: Liad Kaufman <liad.kaufman@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>