sh: arch/sh/kernel/process.c needs asm/fpu.h for unlazy_fpu().

Linus tried to fix up sh fallout from the x86 fpu state cleanup merge and
failed. Add the missing include to get it building again.

  CC      arch/sh/kernel/process.o
arch/sh/kernel/process.c: In function 'arch_dup_task_struct':
arch/sh/kernel/process.c:23:2: error: implicit declaration of function 'unlazy_fpu'

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