m20lte: Symlink /mnt/vendor/efs to /factory

W WVCdm   : [oemcrypto_adapter_dynamic.cpp(916):LoadLevel1] Could not find /factory/wv.keys. Falling Back to L3.

Change-Id: Ie9c34d59679090acad679442e0ce99d4e7dbd522
diff --git a/BoardConfig.mk b/BoardConfig.mk
index 5aec9e6..1e92493 100644
--- a/BoardConfig.mk
+++ b/BoardConfig.mk
@@ -13,7 +13,9 @@
 BOARD_SYSTEMIMAGE_PARTITION_SIZE := 3565158400
 BOARD_RECOVERYIMAGE_PARTITION_SIZE := 39845888
 
-BOARD_ROOT_EXTRA_SYMLINKS := /mnt/vendor/efs:/efs
+BOARD_ROOT_EXTRA_SYMLINKS := \
+    /mnt/vendor/efs:/efs \
+    /mnt/vendor/efs:/factory
 
 # Recovery
 TARGET_RECOVERY_FSTAB := $(DEVICE_PATH)/rootdir/etc/fstab.exynos7904