linux-user: display cpu list.

As it is done for qemu-system with "-cpu ?", when cpu_list_id() is missing
for a target, call cpu_list() instead.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

linux-user/main.c

@@ -2800,6 +2800,8 @@ int main(int argc, char **argv, char **envp)
 /* XXX: implement xxx_cpu_list for targets that still miss it */
 #if defined(cpu_list_id)
                 cpu_list_id(stdout, &fprintf, "");
+#elif defined(cpu_list)
+                cpu_list(stdout, &fprintf); /* deprecated */
 #endif
                 exit(1);
             }