iwlwifi: mvm: add rxf and txf to dump data

When the FW is in error status - try to read the RXF and
TXF (all of them) and add them to the dump data.

This shouldn't happen in non-error statuses, as we don't
want to stop the RXF/TXF while they are running.

Signed-off-by: Liad Kaufman <liad.kaufman@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>