6843041: Remove duplicate README files in repositories (make/README)

Reviewed-by: robilad

make/README

-README:
-  This file should be located at the top of the hotspot Mercurial repository.
-
-  See http://openjdk.java.net/ for more information about the OpenJDK.
-
-  See ../README-builds.html for complete details on build machine requirements.
-
-Simple Build Instructions:
-
-    cd make && gnumake
-     
-  The files that will be imported into the jdk build will be in the "build"
-  directory.
-