Makefile: add dependency of ivshm and kni on ovs target

Add missing dependency from ivshm and kni target on ovs target in main
Makefile.

Change-Id: I0816be241652830cc3453238600330a52072b7b0
Reviewed-by: Mark D. Gray <mark.d.gray@intel.com>
Reviewed-by: Meghan Halton <meghan.halton@intel.com>
Signed-off-by: Nicolas Pernas Maradei <nicolasx.pernas.maradei@intel.com>