accel: Introduce accel_cpu_common_unrealize() stub

Prepare the stub for parity with accel_cpu_common_realize().

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20231003123026.99229-5-philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
diff --git a/cpu.c b/cpu.c
index 1e2649a..2a1eff9 100644
--- a/cpu.c
+++ b/cpu.c
@@ -187,8 +187,10 @@
     cpu_list_remove(cpu);
     /*
      * Now that the vCPU has been removed from the RCU list, we can call
-     * tcg_exec_unrealizefn, which may free fields using call_rcu.
+     * tcg_exec_unrealizefn and
+     * accel_cpu_common_unrealize, which may free fields using call_rcu.
      */
+    accel_cpu_common_unrealize(cpu);
     if (tcg_enabled()) {
         tcg_exec_unrealizefn(cpu);
     }