!454 修正在没有定义lwp时编译出错的问题

Merge pull request !454 from jesven/fix_debug_for_nolwp

libcpu/aarch64/common/context_gcc.S

@@ -144,9 +144,10 @@ rt_hw_get_gtimer_frq:
     /* Set the SP to point to the stack of the task being restored. */
     MOV     SP, X0
 
+#ifdef RT_USING_LWP
     bl      lwp_check_debug
-
     BL      lwp_check_exit
+#endif
 
     LDP     X2, X3, [SP], #0x10  /* SPSR and ELR. */
 
@@ -186,6 +187,7 @@ rt_hw_get_gtimer_frq:
     MOV     SP, X0
 
 #ifdef RT_USING_LWP
+    bl      lwp_check_debug
     bl      lwp_check_exit
 #endif
 

libcpu/arm/cortex-a/context_gcc.S

@@ -246,9 +246,8 @@ rt_hw_context_switch_exit:
     ldmfd   sp!, {r1}
     msr     spsr_cxsf, r1        /* original mode */
 
-    bl lwp_check_debug
-
 #ifdef RT_USING_LWP
+    bl lwp_check_debug
     bl lwp_check_exit
 #endif
 

libcpu/arm/cortex-a/start_gcc.S

@@ -505,9 +505,8 @@ rt_hw_context_switch_interrupt_do:
     ldmfd   sp!, {r4}        /* pop new task's cpsr to spsr */
     msr     spsr_cxsf, r4
 
-    bl      lwp_check_debug
-
 #ifdef RT_USING_LWP
+    bl      lwp_check_debug
     bl      lwp_check_exit
 #endif