添加LPM封装接口

Change-Id: I1f2068902b967286acdfefa83ad2f069a30ffac3
diff --git a/mbtk/libmbtk_lib/Makefile b/mbtk/libmbtk_lib/Makefile
index f067400..4e8ac62 100755
--- a/mbtk/libmbtk_lib/Makefile
+++ b/mbtk/libmbtk_lib/Makefile
@@ -140,7 +140,8 @@
 
 # sleep
 LOCAL_SRC_FILES += \
-    sleep/mbtk_sleep.c
+    sleep/mbtk_sleep.c \
+    sleep/mbtk_lpm.c
 
 #wifi
 LOCAL_SRC_FILES += \