Merge branch 'udp_tunnel_nic-post-conversion-cleanup'

udp_tunnel_nic: post conversion cleanup

It has been two releases since we added the common infra for UDP
tunnel port offload, and we have not heard of any major issues.
Remove the old direct driver NDOs completely, and perform minor
simplifications in the tunnel drivers.

Link: https://lore.kernel.org/r/20210106210637.1839662-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>