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>

init/main.c

@@ -442,9 +442,11 @@ void __init __weak smp_setup_processor_id(void)
 {
 }
 
+# if THREAD_SIZE >= PAGE_SIZE
 void __init __weak thread_info_cache_init(void)
 {
 }
+#endif
 
 /*
  * Set up kernel memory allocators