display-hal: Exclude HWC libs compilation.

This change introduces compilation flag to
compile standalone SDM libs.

Change-Id: I3f8cde50e1806c6cf157364657d77fd9a780d5e3
diff --git a/liblight/Android.mk b/liblight/Android.mk
index 8aff542..ff4825b 100644
--- a/liblight/Android.mk
+++ b/liblight/Android.mk
@@ -20,7 +20,7 @@
 LOCAL_SRC_FILES := lights.c
 LOCAL_MODULE_RELATIVE_PATH := hw
 LOCAL_SHARED_LIBRARIES := liblog
-LOCAL_CFLAGS := $(common_flags) -DLOG_TAG=\"qdlights\"
+LOCAL_CFLAGS := -DLOG_TAG=\"qdlights\"
 LOCAL_CLANG  := true
 LOCAL_MODULE := lights.$(TARGET_BOARD_PLATFORM)
 LOCAL_MODULE_TAGS := optional