tests/qtest/migration: Set q35 as the default machine for x86_86

Change the x86_64 to use the q35 machines in tests from now on. Keep
testing the pc macine on 32bit.

Signed-off-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231018192741.25885-10-farosas@suse.de>

tests/qtest/migration-test.c

@@ -756,7 +756,12 @@ static int test_migrate_start(QTestState **from, QTestState **to,
     got_dst_resume = false;
     if (strcmp(arch, "i386") == 0 || strcmp(arch, "x86_64") == 0) {
         memory_size = "150M";
-        machine_alias = "pc";
+
+        if (g_str_equal(arch, "i386")) {
+            machine_alias = "pc";
+        } else {
+            machine_alias = "q35";
+        }
         arch_opts = g_strdup_printf(
             "-drive if=none,id=d0,file=%s,format=raw "
             "-device ide-hd,drive=d0,secs=1,cyls=1,heads=1", bootpath);