csky: fixup save hi,lo,dspcr regs in switch_stack.

HI, LO, DSPCR registers are 807/810 related regs and no need for 610/860.
All of the regs must be saved in pt_regs and switch_stack. This patch
fixup saving dspcr reg in switch_stack and pt_regs.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>

arch/csky/kernel/ptrace.c

@@ -95,7 +95,9 @@ static int gpr_set(struct task_struct *target,
 		return ret;
 
 	regs.sr = task_pt_regs(target)->sr;
-
+#ifdef CONFIG_CPU_HAS_HILO
+	regs.dcsr = task_pt_regs(target)->dcsr;
+#endif
 	task_thread_info(target)->tp_value = regs.tls;
 
 	*task_pt_regs(target) = regs;