Tools: hv: Prepare to expand kvp_get_ip_address() functionality

kvp_get_ip_address() implemented the functionality to retrieve IP address info.
Make this function more generic so that we could retrieve additional
per-interface information.

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