Tools: hv: Fully support the new KVP verbs in the user level daemon

Tools: hv: Fully support the new KVP verbs in the user level daemon

Now fully support the new KVP messages in the user level daemon. Hyper-V defines
multiple persistent pools to which the host can write/read/modify KVP tuples.
In this patch we implement a file for each specified pool, where the KVP tuples
will be stored in the guest.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit db425334e5bb7fa65bbbd7bea9d79842f65bcf45)

Signed-off-by: Andy Whitcroft <apw@canonical.com>