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/include/asm/processor.h

@@ -11,6 +11,7 @@
 #include <asm/cache.h>
 #include <abi/reg_ops.h>
 #include <abi/regdef.h>
+#include <abi/switch_context.h>
 #ifdef CONFIG_CPU_HAS_FPU
 #include <abi/fpu.h>
 #endif
@@ -50,8 +51,6 @@ struct thread_struct {
 	unsigned long  ksp;       /* kernel stack pointer */
 	unsigned long  sr;        /* saved status register */
 	unsigned long  esp0;      /* points to SR of stack frame */
-	unsigned long  hi;
-	unsigned long  lo;
 
 	/* Other stuff associated with the thread. */
 	unsigned long address;      /* Last user fault */