igc: Add support for source address filters in core

This patch extends MAC address filter internal APIs igc_add_mac_filter()
and igc_del_mac_filter(), as well as local helpers, to support filters
based on source address.

A new parameters 'type' is added to the APIs to indicate if the filter
type is source or destination. In case it is source type, the RAH
register is configured accordingly in igc_set_mac_filter_hw().

Signed-off-by: Andre Guedes <andre.guedes@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>