net/mlx5: Consider PCI domain in search for next dev

The PCI BDF is not unique. PCI domain must also be considered when
searching for the next physical device during lag setup. Example below:

mlx5_core 0000:01:00.0: MLX5E: StrdRq(1) RqSz(8) StrdSz(128) RxCqeCmprss(0)
mlx5_core 0000:01:00.1: MLX5E: StrdRq(1) RqSz(8) StrdSz(128) RxCqeCmprss(0)
mlx5_core 0001:01:00.0: MLX5E: StrdRq(1) RqSz(8) StrdSz(128) RxCqeCmprss(0)
mlx5_core 0001:01:00.1: MLX5E: StrdRq(1) RqSz(8) StrdSz(128) RxCqeCmprss(0)

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Reviewed-by: Aviv Heller <avivh@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>