[MIPS] SB1: On bootup only flush cache on local CPU.

This fixes a warning on bootup warning in smp_call_function.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/mm/c-sb1.c

@@ -505,5 +505,5 @@ void sb1_cache_init(void)
 	:
 	: "memory");
 
-	flush_cache_all();
+	local_sb1___flush_cache_all();
 }