package/diffutils: add DIFFUTILS_CPE_ID_VENDOR

cpe:2.3:a:gnu:diffutils is a valid identifier for
this package:
https://nvd.nist.gov/products/cpe/search/results?namingFormat=2.3&keyword=diffutils

Signed-off-by: Clément Ramirez <clement.ramirez@bootlin.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit e763128b6b16becdb476f52af106302e18c26233)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/diffutils/diffutils.mk

@@ -10,6 +10,7 @@ DIFFUTILS_SITE = $(BR2_GNU_MIRROR)/diffutils
 DIFFUTILS_DEPENDENCIES = $(TARGET_NLS_DEPENDENCIES)
 DIFFUTILS_LICENSE = GPL-3.0+
 DIFFUTILS_LICENSE_FILES = COPYING
+DIFFUTILS_CPE_ID_VENDOR = gnu
 # We're patching m4/stack-direction.m4
 DIFFUTILS_AUTORECONF = YES