[Feature]add MT2731_MP2_MR2_SVN388 baseline version

Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/meta/meta-mediatek/recipes-devtools/clang/llvm-project-source.bbappend b/meta/meta-mediatek/recipes-devtools/clang/llvm-project-source.bbappend
new file mode 100644
index 0000000..5bf7379
--- /dev/null
+++ b/meta/meta-mediatek/recipes-devtools/clang/llvm-project-source.bbappend
@@ -0,0 +1,6 @@
+FILESEXTRAPATHS_append := ":${THISDIR}/files"
+
+SRC_URI_append = " \
+                  file://0002-use-gcc_s-instead-unwind.patch \
+"
+