sky2: handle advanced error recovery config issues

The PCI AER support may not work for a couple of reasons.
It may not be configured into the kernel or there may be a BIOS
bug that prevents MMCONFIG from working.  If MMCONFIG doesn't work
then the PCI registers that control AER will not be accessible via
pci_read_config functions; luckly there is another window to access
PCI space in the device, so use that.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/sky2.h b/drivers/net/sky2.h
index 49ee264..69525fd 100644
--- a/drivers/net/sky2.h
+++ b/drivers/net/sky2.h
@@ -247,7 +247,8 @@
 	B3_PA_CTRL	= 0x01f0,
 	B3_PA_TEST	= 0x01f2,
 
-	Y2_CFG_SPC	= 0x1c00,
+	Y2_CFG_SPC	= 0x1c00,	/* PCI config space region */
+	Y2_CFG_AER      = 0x1d00,	/* PCI Advanced Error Report region */
 };
 
 /*	B0_CTST			16 bit	Control/Status register */