binder: consistent vendor #defines

There is mixed use of __ANDROID_VNDK__
and __ANDROID_VENDOR__, so make sure they
are set consistently.

This is only possible because the VNDK is
deprecated. Before this, __ANDROID_VNDK__
may be set without __ANDROID_VENDOR__ (and I
think some of the logic in libbinder was
probably wrong at that point).

Bug: N/A
Test: N/A
Change-Id: I9cf106ab8309520229ae9e23e7d5c42ab3e425cf
diff --git a/libs/binder/trusty/rules.mk b/libs/binder/trusty/rules.mk
index e0f821f..f2f140d 100644
--- a/libs/binder/trusty/rules.mk
+++ b/libs/binder/trusty/rules.mk
@@ -72,6 +72,7 @@
 	-DBINDER_DISABLE_NATIVE_HANDLE \
 	-DBINDER_DISABLE_BLOB \
 	-DBINDER_NO_LIBBASE \
+	-D__ANDROID_VENDOR__ \
 	-D__ANDROID_VNDK__ \
 
 # libbinder has some deprecated declarations that we want to produce warnings