openvpn: let all openvpn variants provide a virtual openvpn package

Add PROVIDES:=openvpn to the default recipe in order to let all build variants
provide a virtual openvpn package.

The advantage of this approach is that downstream packages can depend on just
"openvpn" without having to require a specific flavor.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

package/network/services/openvpn/Makefile

@@ -10,7 +10,7 @@ include $(TOPDIR)/rules.mk
 PKG_NAME:=openvpn
 
 PKG_VERSION:=2.4.0
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE_URL:=http://swupdate.openvpn.net/community/releases
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
@@ -34,6 +34,7 @@ define Package/openvpn/Default
   MENU:=1
   DEPENDS:=+kmod-tun +OPENVPN_$(1)_ENABLE_LZO:liblzo +OPENVPN_$(1)_ENABLE_IPROUTE2:ip $(3)
   VARIANT:=$(1)
+  PROVIDES:=openvpn
   MAINTAINER:=Mirko Vogt <mirko@openwrt.org>
 endef