Add TARGET_SLSI_VARIANT makefile guard

Change-Id: I3df35a154d6f7bb9bad355a7ea4ad417780c5506
diff --git a/Android.mk b/Android.mk
index 0bbf92f..de582dc 100644
--- a/Android.mk
+++ b/Android.mk
@@ -15,6 +15,7 @@
 # limitations under the License.
 #
 
+ifeq ($(TARGET_SLSI_VARIANT),linaro)
 ifeq ($(TARGET_BOARD_PLATFORM),exynos5)
 
 # exynos5_dirs := \
@@ -23,3 +24,4 @@
 include $(call all-named-subdir-makefiles,$(exynos5_dirs))
 
 endif
+endif