libnftnl: add package CPE ID

Common Platform Enumeration (CPE) is a structured naming scheme for
information technology systems, software, and packages.

Suggested-by: Steffen Pfendtner <[email protected]>
Signed-off-by: Petr Štetiar <[email protected]>

package/libs/libnftnl/Makefile

@@ -8,6 +8,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=libnftnl
+PKG_CPE_ID:=cpe:/a:netfilter:libnftnl
 PKG_VERSION:=1.2.3
 PKG_RELEASE:=$(AUTORELEASE)