net/mlx5: E-switch, Change flow rule destination checking

The checking in the cited commit is not accurate. In the common case,
VF destination is internal, and uplink destination is external.
However, uplink destination with packet reformat is considered as
internal because firmware uses LB+hairpin to support it. Update the
checking so header rewrite rules with both internal and external
destinations are not allowed.

Fixes: e0e22d59 ("net/mlx5: E-switch, Add checking for flow rule destinations")
Signed-off-by: Jianbo Liu <jianbol@nvidia.com>
Reviewed-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>