microblaze: Add missing call to qemu_init_vcpu.

Fixes emulation with io-thread.
Signed-off-by: NPeter A. G. Crosthwaite <peter.crosthwaite@petalogix.com>
Signed-off-by: NEdgar E. Iglesias <edgar.iglesias@gmail.com>

target-microblaze/translate.c

@@ -1850,6 +1850,7 @@ CPUState *cpu_mb_init (const char *cpu_model)
 
     cpu_exec_init(env);
     cpu_reset(env);
+    qemu_init_vcpu(env);
     set_float_rounding_mode(float_round_nearest_even, &env->fp_status);
 
     if (tcg_initialized)