net/mlx5e: Update netdev features after changing XDP state

Some features (LRO, HW GRO) conflict with XDP. If there is an attempt to
enable such features while XDP is active, they will be set to `off
[requested on]`. In order to activate these features after XDP is turned
off, the driver needs to call netdev_update_features(). This commit adds
this missing call after XDP state changes.

Fixes: cf6e34c8 ("net/mlx5e: Properly block LRO when XDP is enabled")
Fixes: b0617e7b

 ("net/mlx5e: Properly block HW GRO when XDP is enabled")
Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>