e1000: switch to symbolic names for pci registers

No functional changes. I verified that the generated
object binary does not change.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NJuan Quintela <quintela@redhat.com>
Acked-by: NGlauber Costa <glommer@gmail.com>

hw/e1000.c

@@ -1089,12 +1089,15 @@ static int pci_e1000_init(PCIDevice *pci_dev)
 
     pci_config_set_vendor_id(pci_conf, PCI_VENDOR_ID_INTEL);
     pci_config_set_device_id(pci_conf, E1000_DEVID);
-    *(uint16_t *)(pci_conf+0x06) = cpu_to_le16(0x0010);
-    pci_conf[0x08] = 0x03;
+    /* TODO: we have no capabilities, so why is this bit set? */
+    pci_set_word(pci_conf + PCI_STATUS, PCI_STATUS_CAP_LIST);
+    pci_conf[PCI_REVISION_ID] = 0x03;
     pci_config_set_class(pci_conf, PCI_CLASS_NETWORK_ETHERNET);
-    pci_conf[0x0c] = 0x10;
+    /* TODO: RST# value should be 0, PCI spec 6.2.4 */
+    pci_conf[PCI_CACHE_LINE_SIZE] = 0x10;
 
-    pci_conf[0x3d] = 1; // interrupt pin 0
+    /* TODO: RST# value should be 0 if programmable, PCI spec 6.2.4 */
+    pci_conf[PCI_INTERRUPT_PIN] = 1; // interrupt pin 0
 
     d->mmio_index = cpu_register_io_memory(e1000_mmio_read,
             e1000_mmio_write, d);