Connector: Add an index to support key/value pair (KVP) functionality

Added a connector index to support key value/pair (KVP) functionality
for Linux guests hosted on a HyperV platform.

Signed-off-by: K. Y. Srinivasan <ksrinivasan@novell.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>