target-moxie: set do_interrupt to a target-specific helper function

The value of "do_interrupt" member of CPUClass shoule be set to a
target-specific function, or it will lead to a segfault like below:

$ moxie-softmmu/qemu-system-moxie -M moxiesim
Segmentation fault

Cc: Anthony Green <green@moxielogic.com>
Cc: Blue Swirl <blauwirbel@gmail.com>
Cc: Andreas Färber <afaerber@suse.de>
Signed-off-by: NDunrong Huang <huangdr@cloud-times.com>
Signed-of-by: NAnthony Green <green@moxielogic.com>
Reviewed-by: NAndreas Färber <afaerber@suse.de>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

target-moxie/cpu.c

@@ -98,6 +98,7 @@ static void moxie_cpu_class_init(ObjectClass *oc, void *data)
     cc->class_by_name = moxie_cpu_class_by_name;
 
     dc->vmsd = &vmstate_moxie_cpu;
+    cc->do_interrupt = moxie_cpu_do_interrupt;
 }
 
 static void moxielite_initfn(Object *obj)

target-moxie/cpu.h

@@ -117,7 +117,7 @@ static inline MoxieCPU *moxie_env_get_cpu(CPUMoxieState *env)
 
 MoxieCPU *cpu_moxie_init(const char *cpu_model);
 int cpu_moxie_exec(CPUMoxieState *s);
-void do_interrupt(CPUMoxieState *env);
+void moxie_cpu_do_interrupt(CPUState *cs);
 void moxie_translate_init(void);
 int cpu_moxie_signal_handler(int host_signum, void *pinfo,
                              void *puc);

target-moxie/helper.c

@@ -102,7 +102,7 @@ void helper_debug(CPUMoxieState *env)
 
 #if defined(CONFIG_USER_ONLY)
 
-void do_interrupt(CPUState *env)
+void moxie_cpu_do_interrupt(CPUState *env)
 {
     env->exception_index = -1;
 }
@@ -147,8 +147,11 @@ int cpu_moxie_handle_mmu_fault(CPUMoxieState *env, target_ulong address,
 }
 
 
-void do_interrupt(CPUMoxieState *env)
+void moxie_cpu_do_interrupt(CPUState *cs)
 {
+    MoxieCPU *cpu = MOXIE_CPU(cs);
+    CPUMoxieState *env = &cpu->env;
+
     switch (env->exception_index) {
     case MOXIE_EX_BREAK:
         break;