sh: Convert to asm-generic/current.h.

Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

arch/sh/include/asm/current.h

-#ifndef __ASM_SH_CURRENT_H
-#define __ASM_SH_CURRENT_H
-
-/*
- * Copyright (C) 1999 Niibe Yutaka
- *
- */
-
-#include <linux/thread_info.h>
-
-struct task_struct;
-
-static __inline__ struct task_struct * get_current(void)
-{
-	return current_thread_info()->task;
-}
-
-#define current get_current()
-
-#endif /* __ASM_SH_CURRENT_H */
+#include <asm-generic/current.h>