Adding makefile for tools/hv

Currently, there is no makefile for the Hyper-V tools.
This patch adds the missing makefile, and adds it to the main tools makefile.

Signed-off-by: Bjarke Istrup Pedersen <gurligebis@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>