package/attr: set ATTR_CPE_ID_VALID

cpe:2.3:a:attr_project:attr is a valid CPE identifier for this package:

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

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/attr/attr.mk

@@ -8,6 +8,7 @@ ATTR_VERSION = 2.4.48
 ATTR_SITE = http://download.savannah.gnu.org/releases/attr
 ATTR_LICENSE = GPL-2.0+ (programs), LGPL-2.1+ (libraries)
 ATTR_LICENSE_FILES = doc/COPYING doc/COPYING.LGPL
+ATTR_CPE_ID_VALID = YES
 
 ATTR_INSTALL_STAGING = YES