team: Fix feature exposure when no ports are present

Small follow-up to align this to an equivalent behavior as the bond driver.
The change in 3625920b ("teaming: fix vlan_features computing") removed
the netdevice vlan_features when there is no team port attached, yet it
leaves the full set of enc_features intact.

Instead, leave the default features as pre 3625920b, and recompute once
we do have ports attached. Also, similarly as in bonding case, call the
netdev_base_features() helper on the enc_features.

Fixes: 3625920b ("teaming: fix vlan_features computing")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20241213123657.401868-1-daniel@iogearbox.net


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