VMCI: guest side driver implementation.

VMCI guest side driver code implementation.
Signed-off-by: NGeorge Zhang <georgezhang@vmware.com>
Acked-by: NAndy king <acking@vmware.com>
Acked-by: NDmitry Torokhov <dtor@vmware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>