FRV: gcc-4.1.2 also inlines weak functions

gcc-4.1.2 inlines weak functions, which causes FRV to fail when the dummy
thread_info_cache_init() gets inlined into start_kernel().

Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/init/main.c b/init/main.c
index 9cf77ab..e33e09d 100644
--- a/init/main.c
+++ b/init/main.c
@@ -442,9 +442,11 @@
 {
 }
 
+# if THREAD_SIZE >= PAGE_SIZE
 void __init __weak thread_info_cache_init(void)
 {
 }
+#endif
 
 /*
  * Set up kernel memory allocators