MIPS: Add board_ebase_setup()

Some systems need to relocate the MIPS exception vector base during
trap initialization.  Add a hook to make this possible.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2959/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/traps.h b/arch/mips/include/asm/traps.h
index 4edab87..ff74aec 100644
--- a/arch/mips/include/asm/traps.h
+++ b/arch/mips/include/asm/traps.h
@@ -24,6 +24,7 @@
 extern void (*board_nmi_handler_setup)(void);
 extern void (*board_ejtag_handler_setup)(void);
 extern void (*board_bind_eic_interrupt)(int irq, int regset);
+extern void (*board_ebase_setup)(void);
 
 extern int register_nmi_notifier(struct notifier_block *nb);