Make bullhead use HWC2to1Adapter in surface flinger

Deprecating old HWC1 code path in favor of HWC2 code path. It still
works by using an adapter HWc2to1 adapter.

Change-Id: I602b2d8d08eeff8c79e6dda30506a42a98065217
diff --git a/BoardConfig.mk b/BoardConfig.mk
index 6c2a540..96d646d 100644
--- a/BoardConfig.mk
+++ b/BoardConfig.mk
@@ -86,6 +86,8 @@
 TARGET_USES_ION := true
 TARGET_USES_C2D_COMPOSITION := true
 TARGET_FORCE_HWC_FOR_VIRTUAL_DISPLAYS := true
+TARGET_USES_HWC2 := true
+TARGET_USES_HWC2ON1ADAPTER := true
 MAX_VIRTUAL_DISPLAY_DIMENSION := 2048
 
 TARGET_AUX_OS_VARIANT_LIST := bullhead