Add missing LwIPLog for bouffalolab platform

Referred to in src/lwip/bl702{,l}/arch/cc.h but not implemented either
in platform (like other platforms did) nor in the bl sdk in third_party.

Signed-off-by: Alexander Mazuruk <aalexanderr@gmail.com>

src/platform/bouffalolab/common/Logging.cpp

@@ -129,3 +129,20 @@ extern "C" void otPlatLog(int aLogLevel, int aLogRegion, const char * aFormat, .
     va_end(v);
 }
 #endif
+
+#if CHIP_SYSTEM_CONFIG_USE_LWIP
+/**
+ * LwIP log output function.
+ */
+extern "C" void LwIPLog(const char * msg, ...)
+{
+    va_list v;
+    uint8_t category = chip::Logging::kLogCategory_Error;
+
+    va_start(v, msg);
+
+    chip::Logging::Platform::LogV("LWIP", category, msg, v);
+
+    va_end(v);
+}
+#endif // #if CHIP_SYSTEM_CONFIG_USE_LWIP