openvswitch: add CONFIG_PACKAGE_openvswitch-python to PKG_BUILD_DEPENDS

That way, OVS gets rebuilt if the openvswitch-python
package is selected or unselected.

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

net/openvswitch/Makefile

@@ -23,7 +23,7 @@ PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=http://openvswitch.org/releases/
 PKG_HASH:=e492cf08a929b4a2178b7f9b01dc4ff562f44138b547b4e942078187b2445d2e
 
-PKG_BUILD_DEPENDS:=python-six/host
+PKG_BUILD_DEPENDS:=python/host python-six/host CONFIG_PACKAGE_openvswitch-python
 
 PKG_BUILD_PARALLEL:=1
 PKG_FIXUP:=autoreconf