Disintegrate asm/system.h for SH

Disintegrate asm/system.h for SH.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-sh@vger.kernel.org
diff --git a/arch/sh/kernel/process_64.c b/arch/sh/kernel/process_64.c
index cbd4e4b..4264583 100644
--- a/arch/sh/kernel/process_64.c
+++ b/arch/sh/kernel/process_64.c
@@ -30,6 +30,7 @@
 #include <asm/pgtable.h>
 #include <asm/mmu_context.h>
 #include <asm/fpu.h>
+#include <asm/switch_to.h>
 
 struct task_struct *last_task_used_math = NULL;