hw/isa/piix3: Resolve redundant k->config_write assignments

The previous patch unified handling of piix3_write_config() accross the
PIIX3 device models which allows for assigning k->config_write once in the
base class.

Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Tested-by: Chuck Zmudzinski <brchuckz@aol.com>
Message-Id: <20230312120221.99183-6-shentey@gmail.com>
Message-Id: <20230403074124.3925-7-shentey@gmail.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>

hw/isa/piix3.c

@@ -322,6 +322,7 @@ static void pci_piix3_class_init(ObjectClass *klass, void *data)
     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
     AcpiDevAmlIfClass *adevc = ACPI_DEV_AML_IF_CLASS(klass);
 
+    k->config_write = piix3_write_config;
     dc->reset       = piix3_reset;
     dc->desc        = "ISA bridge";
     dc->vmsd        = &vmstate_piix3;
@@ -371,7 +372,6 @@ static void piix3_class_init(ObjectClass *klass, void *data)
 {
     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
 
-    k->config_write = piix3_write_config;
     k->realize = piix3_realize;
 }
 
@@ -385,7 +385,6 @@ static void piix3_xen_class_init(ObjectClass *klass, void *data)
 {
     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
 
-    k->config_write = piix3_write_config;
     k->realize = piix3_realize;
 }