package/pkg-utils.mk: expose CPE ID in show-info when available

This commit exposes a new per-package property in the "make show-info"
JSON output: "cpe-id", which exists when a valid CPE ID is available
for the package.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Reviewed-by: Matt Weber <matthew.weber@rockwellcollins.com>
Tested-by: Heiko Thiery <heiko.thiery@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/pkg-utils.mk

@@ -119,6 +119,9 @@ define _json-info-pkg
 	"reverse_dependencies": [
 		$(call make-comma-list,$(sort $($(1)_RDEPENDENCIES)))
 	]
+	$(if $($(1)_CPE_ID_VALID), \
+		$(comma) "cpe-id": "$($(1)_CPE_ID)" \
+	)
 	$(if $($(1)_IGNORE_CVES),
 		$(comma) "ignore_cves": [
 			$(call make-comma-list,$(sort $($(1)_IGNORE_CVES)))