package/libupnp: set LIBUPNP_CPE_ID_VALID

cpe:2.3:a:libupnp_project:libupnp is indeed the right CPE identifier
for this package, as can be seen from:

  https://nvd.nist.gov/products/cpe/search/results?namingFormat=2.3&keyword=cpe%3A2.3%3Aa%3Alibupnp_project%3Alibupnp

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/libupnp/libupnp.mk

@@ -11,5 +11,6 @@ LIBUPNP_CONF_ENV = ac_cv_lib_compat_ftime=no
 LIBUPNP_INSTALL_STAGING = YES
 LIBUPNP_LICENSE = BSD-3-Clause
 LIBUPNP_LICENSE_FILES = LICENSE
+LIBUPNP_CPE_ID_VALID = YES
 
 $(eval $(autotools-package))