msf2: Unbreak device-list-properties for "msf-soc"

Watch this:

    $ qemu-system-aarch64 -M ast2600-evb -S -display none -qmp stdio
    {"QMP": {"version": {"qemu": {"micro": 50, "minor": 0, "major": 5}, "package": "v5.0.0-2464-g3a9163af4e"}, "capabilities": ["oob"]}}
    {"execute": "qmp_capabilities"}
    {"return": {}}
    {"execute": "device-list-properties", "arguments": {"typename": "msf2-soc"}}
    Unsupported NIC model: ftgmac100
    armbru@dusky:~/work/images$ echo $?
    1

This is what breaks "make check SPEED=slow".

Root cause is m2sxxx_soc_initfn()'s messing with nd_table[] via
qemu_check_nic_model().  That's wrong.

We fixed the exact same bug for device "allwinner-a10" in commit
8aabc5437b "hw/arm/allwinner-a10: Do not use nd_table in instance_init
function".  Fix this instance the same way: move the offending code to
m2sxxx_soc_realize(), where it's less wrong, and add a FIXME comment.

Fixes: 05b7374a58 ("msf2: Add EMAC block to SmartFusion2 SoC")
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200715140440.3540942-2-armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

hw/arm/msf2-soc.c

@@ -82,10 +82,6 @@ static void m2sxxx_soc_initfn(Object *obj)
     }
 
     object_initialize_child(obj, "emac", &s->emac, TYPE_MSS_EMAC);
-    if (nd_table[0].used) {
-        qemu_check_nic_model(&nd_table[0], TYPE_MSS_EMAC);
-        qdev_set_nic_properties(DEVICE(&s->emac), &nd_table[0]);
-    }
 }
 
 static void m2sxxx_soc_realize(DeviceState *dev_soc, Error **errp)
@@ -187,6 +183,11 @@ static void m2sxxx_soc_realize(DeviceState *dev_soc, Error **errp)
         g_free(bus_name);
     }
 
+    /* FIXME use qdev NIC properties instead of nd_table[] */
+    if (nd_table[0].used) {
+        qemu_check_nic_model(&nd_table[0], TYPE_MSS_EMAC);
+        qdev_set_nic_properties(DEVICE(&s->emac), &nd_table[0]);
+    }
     dev = DEVICE(&s->emac);
     object_property_set_link(OBJECT(&s->emac), "ahb-bus",
                              OBJECT(get_system_memory()), &error_abort);