Staging: hv: Remove the vm_device structure

Consolidate all device related state in struct hv_device by
moving the device field from struct vm_device to
struct hv_device. As part of this, also get rid of struct
vm_device since the consolidation is complete.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Abhishek Kane <v-abkane@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>