wpantund: Fix build break with missing strlcpy symbol

The wpantund project has some m4 macro to check for strlcpy and strlcat
being available. We are hitting a corner case here (maybe due to musl)
where strlcpy is detected but the system still does not build.

Adding a patch to the project to fix this case which was also submitted
upstream and waits for review.

Signed-off-by: Stefan Schmidt <stefan.schmidt@huawei.com>

meta-ohos-staging/recipes-connectivity/openthread/wpantund/0001-util-netif-mgmt-only-include-missing-strlcpy-header-.patch

+From 797c56efbb8aa8653549a4e4a38d4c9f2ceace28 Mon Sep 17 00:00:00 2001
+From: Stefan Schmidt <stefan.schmidt@huawei.com>
+Date: Fri, 21 May 2021 22:44:31 +0200
+Subject: [PATCH] util/netif-mgmt: only include missing strlcpy header if
+ actually missing
+
+In commit 4e2ef143046a0c89afe6fd66acf5b7a7f35e8356 this header was
+added unconditionally. For my system (Yocto with musl) this results in
+strlcpy being redefined to __missing_strlcpy in all cases. No matter if
+strlcpy is available or not.
+
+Given it is available and the nl.m4 macros detects this, the libstrlcpy.la
+helper is not built which results in:
+
+netif-mgmt.c:386: more undefined references to `___missing_strlcpy' follow
+
+Upstream-Status: Submitted [https://github.com/openthread/wpantund/pull/497]
+
+Signed-off-by: Stefan Schmidt <stefan.schmidt@huawei.com>
+---
+ src/util/netif-mgmt.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/src/util/netif-mgmt.c b/src/util/netif-mgmt.c
+index 3fffb2e..8fa0107 100644
+--- a/src/util/netif-mgmt.c
++++ b/src/util/netif-mgmt.c
+@@ -69,7 +69,9 @@
+ #define IFEF_NOAUTOIPV6LL   0x2000  /* Interface IPv6 LinkLocal address not provided by kernel */
+ #endif
+ 
++#ifdef MISSING_STRLCPY
+ #include "missing/strlcpy/strlcpy.h"
++#endif
+ 
+ #ifndef SIOCSIFLLADDR
+ #define SIOCSIFLLADDR SIOCSIFHWADDR

meta-ohos-staging/recipes-connectivity/openthread/wpantund_git.bb

@@ -13,7 +13,9 @@ LIC_FILES_CHKSUM = "file://LICENSE;md5=e7820bc7f7d1638a6b54fc2e8d7fb103 \
                     file://third_party/pt/LICENSE;md5=dcd598b69cad786beea33da7b1ae14b7 \
                     "
 
-SRC_URI = "gitsm://github.com/openthread/wpantund.git;protocol=https"
+SRC_URI = "gitsm://github.com/openthread/wpantund.git;protocol=https \
+           file://0001-util-netif-mgmt-only-include-missing-strlcpy-header-.patch \
+           "
 
 PV = "0.07.01+git${SRCPV}"
 SRCREV = "820468161c87816a3e94366ebbe2a932650416e3"