fixed s3c2440a context thread bug,patch contributor

:yuxun2k

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2192 bbd45198-f89e-11dd-88c7-29a3b14d5316

libcpu/arm/s3c24x0/context_gcc.S

@@ -58,9 +58,9 @@ rt_hw_context_switch:
 	ldmfd	sp!, {r4}		@ pop new task spsr
 	msr	spsr_cxsf, r4
 	ldmfd	sp!, {r4}		@ pop new task cpsr
-	msr	cpsr_cxsf, r4
+	msr	spsr_cxsf, r4
 
-	ldmfd	sp!, {r0-r12, lr, pc}	@ pop new task r0-r12, lr & pc
+	ldmfd	sp!, {r0-r12, lr, pc}^	@ pop new task r0-r12, lr & pc
 
 /*
  * void rt_hw_context_switch_to(rt_uint32 to);

libcpu/arm/s3c24x0/context_rvds.S

@@ -60,9 +60,9 @@ rt_hw_context_switch	PROC
 	LDMFD	sp!, {r4}			; pop new task spsr
 	MSR	spsr_cxsf, r4
 	LDMFD	sp!, {r4}			; pop new task cpsr
-	MSR	cpsr_cxsf, r4
+	MSR	spsr_cxsf, r4
 
-	LDMFD	sp!, {r0-r12, lr, pc}	; pop new task r0-r12, lr & pc
+	LDMFD	sp!, {r0-r12, lr, pc}^	; pop new task r0-r12, lr & pc
 	ENDP
 
 ;/*