i40e: reset veb.tc_stats when resetting veb.stats

The stats structure for the VEB switch statistics is reset periodically,
but the tc_stats are not reset at the same time.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>