ice: Disallow VF VLAN opcodes if VLAN offloads disabled

Currently if the host disables VLAN offloads on the VF by
not setting the VIRTCHNL_VF_OFFLOAD_VLAN capability bit
we will still honor VF VLAN configuration messages over
VIRTCHNL. These messages (i.e. enable/disable VLAN stripping
and VLAN filtering) should be blocked when the feature
is not supported. Fix that by adding a helper function to
determine if the VF is allowed to do VLAN operations based
on the host's VF configuration.

Also, mirror the VF communicated capabilities in the host's
VF configuration.

Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>