cpu: Replace do_interrupt() by CPUClass::do_interrupt method

This removes a global per-target function and thus takes us one step
closer to compiling multiple targets into one executable.

It will also allow to override the interrupt handling for certain CPU
families.

Signed-off-by: Andreas Färber <afaerber@suse.de>
diff --git a/target-cris/helper.c b/target-cris/helper.c
index 885f67f..e1ef7bc 100644
--- a/target-cris/helper.c
+++ b/target-cris/helper.c
@@ -36,8 +36,11 @@
 
 #if defined(CONFIG_USER_ONLY)
 
-void do_interrupt(CPUCRISState *env)
+void cris_cpu_do_interrupt(CPUState *cs)
 {
+    CRISCPU *cpu = CRIS_CPU(cs);
+    CPUCRISState *env = &cpu->env;
+
     env->exception_index = -1;
     env->pregs[PR_ERP] = env->pc;
 }
@@ -162,9 +165,10 @@
                   env->pregs[PR_ERP]);
 }
 
-void do_interrupt(CPUCRISState *env)
+void cris_cpu_do_interrupt(CPUState *cs)
 {
-    D(CPUState *cs = CPU(cris_env_get_cpu(env)));
+    CRISCPU *cpu = CRIS_CPU(cs);
+    CPUCRISState *env = &cpu->env;
     int ex_vec = -1;
 
     if (env->pregs[PR_VR] < 32) {