coverity: mediatek mt8189 platform build

Change-Id: Icc1d31071507b93581ff438469b8d56e547413b4
Signed-off-by: Gavin Liu <gavin.liu@mediatek.com>
diff --git a/tf_config/mt8189-default b/tf_config/mt8189-default
new file mode 100644
index 0000000..0b4cc92
--- /dev/null
+++ b/tf_config/mt8189-default
@@ -0,0 +1,3 @@
+COREBOOT=1
+CROSS_COMPILE=aarch64-none-elf-
+PLAT=mt8189