vendor: set WITH_DEXPREOPT := false for HOMEMADE by default

who really wants to have DEXPREOPT there???

Change-Id: I73f18adeedd356f455b0c43d26bfb20ea106907a
diff --git a/config/common.mk b/config/common.mk
index 9bd99a0..0dddf76 100644
--- a/config/common.mk
+++ b/config/common.mk
@@ -82,3 +82,7 @@
 ifeq ($(ROM_BUILDTYPE),SECURITY_RELEASE)
     WITH_DEXPREOPT := true
 endif
+# but not homemades
+ifeq ($(ROM_BUILDTYPE),HOMEMADE)
+    WITH_DEXPREOPT := false
+endif