aspeed/smc: Let the SSI core layer define the bus name

If no id is provided, qdev automatically assigns an unique name with
the following pattern "<type>.<index>" which avoids bus name collision
when using multiple buses.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220307071856.1410731-6-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

hw/ssi/aspeed_smc.c

@@ -1130,7 +1130,7 @@ static void aspeed_smc_realize(DeviceState *dev, Error **errp)
     /* DMA irq. Keep it first for the initialization in the SoC */
     sysbus_init_irq(sbd, &s->irq);
 
-    s->spi = ssi_create_bus(dev, "spi");
+    s->spi = ssi_create_bus(dev, NULL);
 
     /* Setup cs_lines for peripherals */
     s->cs_lines = g_new0(qemu_irq, asc->cs_num_max);