staging: fsl-dpaa2/ethsw: Add comments to ETHSW_VLAN flags

Document each ETHSW_VLAN flag with the appropriate comment.

Signed-off-by: Razvan Stefanescu <razvan.stefanescu@nxp.com>
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/1562336836-17119-7-git-send-email-ioana.ciornei@nxp.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>