package/libcoap: add CPE ID

libcoap:libcoap is a valid CPE ID:
https://nvd.nist.gov/products/cpe/detail/FA3B1D63-B4E6-4EAD-A2C9-CE4E52D83E37?namingFormat=2.3&orderBy=CPEURI&keyword=libcoap&status=FINAL

Signed-off-by: Daniel Lang <dalang@gmx.at>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit cd379c7224e584e46b589d5483a2eeda7eafe6f4)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libcoap/libcoap.mk

@@ -9,6 +9,7 @@ LIBCOAP_SITE = $(call github,obgm,libcoap,v$(LIBCOAP_VERSION))
 LIBCOAP_INSTALL_STAGING = YES
 LIBCOAP_LICENSE = BSD-2-Clause
 LIBCOAP_LICENSE_FILES = COPYING LICENSE
+LIBCOAP_CPE_ID_VENDOR = libcoap
 LIBCOAP_DEPENDENCIES = host-pkgconf
 LIBCOAP_CONF_OPTS = \
 	--disable-examples --disable-examples-source --without-tinydtls