net/mlx5: SF, Consider own vhca events of SF devices

Vhca events on eswitch manager are received for all the functions on the
NIC, including for SFs of external host PF controllers.

While SF device handler is only interested in SF devices events related
to its own PF.
Hence, validate if the function belongs to self or not.

Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Vu Pham <vuhuong@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>