wifi: mac80211: Create separate links for VLAN interfaces

Currently, MLD links for an AP_VLAN interface type is not fully
supported.

Add allocation of separate links for each VLAN interface and copy
chanctx and chandef of master AP to VLAN where necessary. Separate
links are created because for Dynamic VLAN each link will have its own
default_multicast_key.

Signed-off-by: Muna Sinada <muna.sinada@oss.qualcomm.com>
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>