sh64: add missing #include <asm/fpu.h>'s

This patch fixes some compile errors due to missing save_fpu()
prototypes on sh64 caused by
commit 9bbafce2ee
(sh: Fix occasional FPU register corruption under preempt).

Signed-off-by: Adrian Bunk <adrian.bunk@movial.fi>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/traps_64.c

@@ -30,6 +30,7 @@
 #include <asm/atomic.h>
 #include <asm/processor.h>
 #include <asm/pgtable.h>
+#include <asm/fpu.h>
 
 #undef DEBUG_EXCEPTION
 #ifdef DEBUG_EXCEPTION