Fixes#50
This is done for decoupling device management part from other parts.
It seperate device.go to several dirs and files:
```
virtcontainers/device
├── api
│ └── interface.go
├── config
│ └── config.go
├── drivers
│ ├── block.go
│ ├── generic.go
│ ├── utils.go
│ ├── vfio.go
│ ├── vhost_user_blk.go
│ ├── vhost_user.go
│ ├── vhost_user_net.go
│ └── vhost_user_scsi.go
└── manager
├── manager.go
└── utils.go
```
* `api` contains interface definition of device management, so upper level caller
should import and use the interface, and lower level should implement the interface.
it's bridge to device drivers and callers.
* `config` contains structed exported data.
* `drivers` contains specific device drivers including block, vfio and vhost user
devices.
* `manager` exposes an external management package with a `DeviceManager`.
Signed-off-by: Zhang Wei <zhangwei555@huawei.com>
When imported, the vc files carried in the 'full style' apache
license text, but the standard for kata is to use SPDX style.
Update the relevant files to SPDX.
Fixes: #227
Signed-off-by: Graham whaley <graham.whaley@intel.com>
