net: openvswitch: Fix kerneldoc warnings

net: openvswitch: Fix kerneldoc warnings

net/openvswitch/flow.c:303: warning: Function parameter or member 'key_vh' not described in 'parse_vlan_tag'
net/openvswitch/flow.c:303: warning: Function parameter or member 'skb' not described in 'parse_vlan_tag'
net/openvswitch/flow.c:303: warning: Function parameter or member 'untag_vlan' not described in 'parse_vlan_tag'
net/openvswitch/vport.c:122: warning: Function parameter or member 'parms' not described in 'ovs_vport_alloc'

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20201028004849.930094-1-andrew@lunn.ch
Signed-off-by: Jakub Kicinski <kuba@kernel.org>