hw/arm/aspeed: Correct spi_model w25q256 for ast1030-a1 EVB.

Currently, the default spi_model was "sst25vf032b" whose size was 4MB for
ast1030-a1 EVB. However, according to the schematic of ast1030-a1 EVB,
ASPEED shipped default flash of spi1 and spi2 were w25q256 whose size
was 32MB.

Correct spi_model default flash to w25q256 for ast1030-a1 EVB.

Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>

hw/arm/aspeed.c

@@ -1643,7 +1643,7 @@ static void aspeed_minibmc_machine_ast1030_evb_class_init(ObjectClass *oc,
     amc->i2c_init = ast1030_evb_i2c_init;
     mc->default_ram_size = 0;
     amc->fmc_model = "sst25vf032b";
-    amc->spi_model = "sst25vf032b";
+    amc->spi_model = "w25q256";
     amc->num_cs = 2;
     amc->macs_mask = 0;
     aspeed_machine_class_init_cpus_defaults(mc);