cassini: Fix build bustage on x86.

Unfortunately, not all CONFIG_OF platforms provide
pci_device_to_OF_node().

Change the test to CONFIG_SPARC for now to deal with
the build regressions.

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/cassini.c

@@ -3203,7 +3203,7 @@ static int cas_get_vpd_info(struct cas *cp, unsigned char *dev_addr,
 	int phy_type = CAS_PHY_MII_MDIO0; /* default phy type */
 	int mac_off  = 0;
 
-#if defined(CONFIG_OF)
+#if defined(CONFIG_SPARC)
 	const unsigned char *addr;
 #endif
 
@@ -3354,7 +3354,7 @@ use_random_mac_addr:
 	if (found & VPD_FOUND_MAC)
 		goto done;
 
-#if defined(CONFIG_OF)
+#if defined(CONFIG_SPARC)
 	addr = of_get_property(cp->of_node, "local-mac-address", NULL);
 	if (addr != NULL) {
 		memcpy(dev_addr, addr, 6);
@@ -5031,7 +5031,7 @@ static int __devinit cas_init_one(struct pci_dev *pdev,
 	cp->msg_enable = (cassini_debug < 0) ? CAS_DEF_MSG_ENABLE :
 	  cassini_debug;
 
-#if defined(CONFIG_OF)
+#if defined(CONFIG_SPARC)
 	cp->of_node = pci_device_to_OF_node(pdev);
 #endif