Makefile.am: fix #18867 to include README.dev in dist file

Makefile.am

@@ -159,7 +159,7 @@ else
 txtdir = ${docdir}
 endif
 txt_DATA = AUTHORS COPYING.LGPL README README.dev STARPU-REVISION
-EXTRA_DIST = autogen.sh AUTHORS COPYING.LGPL README STARPU-VERSION STARPU-REVISION build-aux/svn2cl.xsl mic-configure
+EXTRA_DIST = autogen.sh AUTHORS COPYING.LGPL README README.dev STARPU-VERSION STARPU-REVISION build-aux/svn2cl.xsl mic-configure
 
 DISTCLEANFILES = STARPU-REVISION