ice: Allow egress control packets from PF_VSI

ice: Allow egress control packets from PF_VSI

For control packets (i.e. LLDP packets) to be able to egress
from the main VSI, a bit has to be set in the TX_descriptor.
This should only be done for the main VSI and only if the
FW LLDP agent is disabled.  A bit to allow this also has to
be set in the VSI context.

Add the logic to add the necessary bits in the VSI context
for the PF_VSI and the TX_descriptors for control packets
egressing the PF_VSI.

Signed-off-by: Dave Ertman <david.m.ertman@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>