qapi: Convert migrate_set_speed

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
diff --git a/hmp.c b/hmp.c
index 04e6b73..e7659d5 100644
--- a/hmp.c
+++ b/hmp.c
@@ -673,3 +673,9 @@
     double value = qdict_get_double(qdict, "value");
     qmp_migrate_set_downtime(value, NULL);
 }
+
+void hmp_migrate_set_speed(Monitor *mon, const QDict *qdict)
+{
+    int64_t value = qdict_get_int(qdict, "value");
+    qmp_migrate_set_speed(value, NULL);
+}