net/mlx5: Rename mlx5_pci_dev_type to mlx5_coredev_type

Rename mlx5_pci_dev_type to mlx5_coredev_type to distinguish different mlx5
device types.

mlx5_coredev_type represents mlx5_core_dev instance type. Hence keep
mlx5_coredev_type in mlx5_core_dev structure.

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