package/sdl2: add CPE variables

cpe:2.3:a:libsdl:sdl is a valid CPE identifier for this package:

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

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/sdl2/sdl2.mk

@@ -9,6 +9,8 @@ SDL2_SOURCE = SDL2-$(SDL2_VERSION).tar.gz
 SDL2_SITE = http://www.libsdl.org/release
 SDL2_LICENSE = Zlib
 SDL2_LICENSE_FILES = COPYING.txt
+SDL2_CPE_ID_VENDOR = libsdl
+SDL2_CPE_ID_PRODUCT = sdl
 SDL2_INSTALL_STAGING = YES
 SDL2_CONFIG_SCRIPTS = sdl2-config