common/mlx5: add getter functions on Windows

Add file mlx5/windows/mlx5_common_os.h the equivalent of Linux file
mlx5/linux/mlx5_common_os.h. It contains getters functions
mlx5_os_get_dev_device_name, mlx5_os_get_ctx_device_name,
mlx5_os_get_ctx_device_path, mlx5_os_get_umem_id,
mlx5_os_get_devx_channel_fd.

Signed-off-by: Ophir Munk <ophirmu@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>