i40e: check vsi type before setting xdp_features flag

Set xdp_features flag just for I40E_VSI_MAIN vsi type since XDP is
supported just in this configuration.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/f2b537f86b34fc176fbc6b3d249b46a20a87a2f3.1676405131.git.lorenzo@kernel.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>