hv: move "device_id" bus attribute to dev_groups

This moves the "device_id" bus attribute to the dev_groups structure,
removing the need for it to be in a temporary structure.

Tested-by: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>