package/chartjs: add CPE variables

cpe:2.3:a:chartjs:chart.js is a valid CPE identifier for this package:

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

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

package/chartjs/chartjs.mk

@@ -8,6 +8,8 @@ CHARTJS_VERSION = 2.9.4
 CHARTJS_SITE = $(call github,chartjs,Chart.js,v$(CHARTJS_VERSION))
 CHARTJS_LICENSE = MIT
 CHARTJS_LICENSE_FILES = LICENSE.md
+CHARTJS_CPE_ID_VENDOR = chartjs
+CHARTJS_CPE_ID_PRODUCT = chart.js
 
 define CHARTJS_INSTALL_TARGET_CMDS
 	$(INSTALL) -m 0644 -D $(@D)/dist/Chart.min.css \