Refactor grouper build.

Change-Id: Ibdf67c5dc4aa839171e2a36981d7d01acfa4ebfa
diff --git a/Android.mk b/Android.mk
index bac9337..94650f0 100644
--- a/Android.mk
+++ b/Android.mk
@@ -14,7 +14,7 @@
 
 LOCAL_PATH := $(call my-dir)
 
-ifneq ($(filter grouper,$(TARGET_DEVICE)),)
+ifneq ($(filter grouper tilapia,$(TARGET_DEVICE)),)
 include $(call all-makefiles-under,$(LOCAL_PATH))
 -include vendor/nvidia/common/TegraBoard.mk
 endif
diff --git a/BoardConfigCommon.mk b/BoardConfigCommon.mk
index 2613d0f..26131fb 100644
--- a/BoardConfigCommon.mk
+++ b/BoardConfigCommon.mk
@@ -77,3 +77,5 @@
 NEED_WORKAROUND_CORTEX_A9_745320 := true
 
 TARGET_RELEASETOOLS_EXTENSIONS := device/asus/grouper
+
+BOARD_USES_GROUPER_MODULES := true