Fix LED build error.

Change-Id: I4a7276c5704d1446a5f6dbcd7c5868e3e73b3d99
diff --git a/mbtk/libmbtk_lib/Makefile b/mbtk/libmbtk_lib/Makefile
index abb76bc..fa177ac 100755
--- a/mbtk/libmbtk_lib/Makefile
+++ b/mbtk/libmbtk_lib/Makefile
@@ -79,9 +79,12 @@
 	common/mbtk_version.c \
 	common/mbtk_gpio.c \
 	common/mbtk_adc.c \
-	common/mbtk_led_control.c \
 	common/mbtk_loopbuff.c
 
+ifeq ($(MBTK_SOURCE_VERSION), 2)
+LOCAL_SRC_FILES += common/mbtk_led_control.c
+endif
+
 # audio
 LOCAL_SRC_FILES += \
     audio/mbtk_audio.c \