aec62xx: Fix kernel oops in driver's probe function

Add pci_enable_device() to aec62xx probe function
before doing any I/O.

Original probe function tries to read from device's
PCI region 4 before calling ide_setup_pci_device().
Since the device is not enabled at this point,
on machines that have no firmware PCI initialization
(e.g. ASUS WL-700gE router), corresponding PCI BAR 
is 0 and the following inb() causes a kernel oops.

Signed-off-by: Aleksandar Radovanovic <biblbroks@sezampro.yu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/pci/aec62xx.c b/drivers/ide/pci/aec62xx.c
index 19ec421..4426850 100644
--- a/drivers/ide/pci/aec62xx.c
+++ b/drivers/ide/pci/aec62xx.c
@@ -260,6 +260,11 @@
 {
 	struct ide_port_info d;
 	u8 idx = id->driver_data;
+	int err;
+
+	err = pci_enable_device(dev);
+	if (err)
+		return err;
 
 	d = aec62xx_chipsets[idx];
 
@@ -272,7 +277,11 @@
 		}
 	}
 
-	return ide_setup_pci_device(dev, &d);
+	err = ide_setup_pci_device(dev, &d);
+	if (err)
+		pci_disable_device(dev);
+
+	return err;
 }
 
 static const struct pci_device_id aec62xx_pci_tbl[] = {