Staging: hv: util: Properly handle util services in the util driver

Now, properly handle util services in the util driver and eliminate code
that will not be necessary. In the current code, util services were
all handled not as other vmbus devices (net, block) but rather through
special handling (channel setup etc.). In this patch we handle all
services using the standard Linux Driver Model.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>