[MIPS] Introduce _machine_restart

Handles machine specific functions by using weak functions.

Signed-off-by: Shinya Kuribayashi <skuribay@ruby.dti.ne.jp>

include/asm-mips/reboot.h

@@ -0,0 +1,14 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1997, 1999, 2001, 06 by Ralf Baechle
+ * Copyright (C) 2001 MIPS Technologies, Inc.
+ */
+#ifndef _ASM_REBOOT_H
+#define _ASM_REBOOT_H
+
+extern void _machine_restart(void);
+
+#endif /* _ASM_REBOOT_H */