package/tinyxml: add CVE trailer in patch

Since Buildroot commit [1] the patches that fixes a security
vulnerability needs to reference the fixed vulnerability.

This patch adds the relevant information to the patch header
and adds the `Upstream` trailer.

[1] 1167d0ff3d docs/manual: mention CVE trailer

Signed-off-by: Thomas Perale <thomas.perale@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit 7b8c58ae03)
Signed-off-by: Thomas Perale <thomas.perale@mind.be>

.checkpackageignore

@@ -1103,7 +1103,6 @@ package/tinyalsa/0001-include-time.h-before-asound.h.patch lib_patch.Upstream
 package/tinycbor/0001-Makefile-add-DISABLE_WERROR.patch lib_patch.Upstream
 package/tinycompress/0001-wave-add-time.h-missing-header-inclusion.patch lib_patch.Upstream
 package/tinydtls/0001-sha2-sha2.c-fix-build-on-big-endian.patch lib_patch.Upstream
-package/tinyxml/0001-In-stamp-always-advance-the-pointer-if-p-0xef.patch lib_patch.Upstream
 package/tpm2-abrmd/S80tpm2-abrmd Shellcheck lib_sysv.Indent lib_sysv.Variables
 package/tpm2-tss/0001-Temporary-fix-for-build-without-C.patch lib_patch.Upstream
 package/transmission/S92transmission Shellcheck lib_sysv.ConsecutiveEmptyLines lib_sysv.Indent lib_sysv.Variables

package/tinyxml/0001-In-stamp-always-advance-the-pointer-if-p-0xef.patch

@@ -8,8 +8,8 @@ by two non-zero bytes. In case of malformed input (0xef should be
 the start byte of a three byte character) this leads to an infinite
 loop. (CVE-2021-42260)
 
-[Retrieved (and backported) from:
-https://sourceforge.net/p/tinyxml/git/merge-requests/1]
+CVE: CVE-2021-42260
+Upstream: https://sourceforge.net/p/tinyxml/git/merge-requests/1
 Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
 ---
  tinyxmlparser.cpp | 6 ++++++