nfp: flower: configure tunnel neighbour on cmsg rx

nfp_tun_write_neigh() function will configure a tunnel neighbour when
calling nfp_tun_neigh_event_handler() or nfp_flower_cmsg_process_one_rx()
(with no tunnel neighbour type) from firmware.

When configuring IP on physical port as a tunnel endpoint, no operation
will be performed after receiving the cmsg mentioned above.

Therefore, add a progress to configure tunnel neighbour in this case.

v2: Correct format of fixes tag.

Fixes: f1df7956

 ("nfp: flower: rework tunnel neighbour configuration")
Signed-off-by: Tianyu Yuan <tianyu.yuan@corigine.com>
Reviewed-by: Louis Peens <louis.peens@corigine.com>
Reviewed-by: Baowen Zheng <baowen.zheng@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20220714081915.148378-1-simon.horman@corigine.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>