Remove obsolete brillo property

The implementation behind this cflag has already been removed.

Test: none
Change-Id: Ida61c64f86180c8a7d41b6af7036312ebe0dd3d4
diff --git a/libs/gui/Android.bp b/libs/gui/Android.bp
index cf72d55..a302f28 100644
--- a/libs/gui/Android.bp
+++ b/libs/gui/Android.bp
@@ -66,9 +66,6 @@
     ],
 
     product_variables: {
-        brillo: {
-            cflags: ["-DHAVE_NO_SURFACE_FLINGER"],
-        },
         eng: {
             cppflags: [
                 "-UDEBUG_ONLY_CODE",