i40e: store MAC/VLAN filters in a hash with the MAC Address as key

Replace the mac_filter_list with a static size hash table of 8bits. The
primary advantage of this is a decrease in latency of operations related
to searching for specific MAC filters, including .set_rx_mode. Using
a linked list resulted in several locations which were O(n^2). Using
a hash table should give us latency growth closer to O(n*log(n)).

Change-ID: I5330bd04053b880e670210933e35830b95948ebb
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>