virtchnl: Use pad byte in virtchnl_ether_addr to specify MAC type

virtchnl: Use pad byte in virtchnl_ether_addr to specify MAC type

Currently, there is no way for a VF driver to specify that it wants to
change its device/primary unicast MAC address. This makes it
difficult/impossible for the PF driver to track the VF's device/primary
unicast MAC address, which is used for VM/VF reboot and displaying on
the host. Fix this by using 2 bits of a pad byte in the
virtchnl_ether_addr structure so the VF can specify what type of MAC
it's adding/deleting.

Below are the values that should be used by all VF drivers going
forward.

VIRTCHNL_ETHER_ADDR_LEGACY(0):
	- The type should only ever be 0 for legacy AVF drivers (i.e.
	  drivers that don't support the new type bits). The PF drivers
	  will track VF's device/primary unicast MAC, but this will only
	  be a best effort.

VIRTCHNL_ETHER_ADDR_PRIMARY(1):
	- This type should only be used when the VF is changing their
	  device/primary unicast MAC. It should be used for both delete
	  and add cases related to the device/primary unicast MAC.

VIRTCHNL_ETHER_ADDR_EXTRA(2):
	- This type should be used when the VF is adding and/or deleting
	  MAC addresses that are not the device/primary unicast MAC. For
	  example, extra unicast addresses and multicast addresses
	  assuming the PF supports "extra" addresses at all.

If a PF is parsing the type field of the virtchnl_ether_addr, then it
should use the VIRTCHNL_ETHER_ADDR_TYPE_MASK to mask the first two bits
of the type field since 0, 1, and 2 are the only valid values.

Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>