mark *-knetbsd-* as obsolete

gcc/ChangeLog:

2015-12-17  Trevor Saunders  <tbsaunde+gcc@tbsaunde.org>

	* config.gcc: Mark knetbsd targets as obsolete.

From-SVN: r231772

gcc/ChangeLog

+2015-12-17  Trevor Saunders  <tbsaunde+gcc@tbsaunde.org>
+
+	* config.gcc: Mark knetbsd targets as obsolete.
+
 2015-12-17  Nathan Sidwell  <nathan@acm.org>
 
 	* config/nvptx/nvptx.h (NVPTX_RETURN_REGNUM, FRAME_POINTER_REGNUM,

gcc/config.gcc

@@ -236,8 +236,7 @@ md_file=
 
 # Obsolete configurations.
 case ${target} in
-# Currently there are no obsolete targets.
- nothing				\
+ *-knetbsd-*				\
  )
     if test "x$enable_obsolete" != xyes; then
       echo "*** Configuration ${target} is obsolete." >&2