frv: remove dead config symbol from FRV code

Remove dead config symbol from FRV code.

Signed-off-by: Jiri Olsa <olsajiri@gmail.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>