AHCI: Make distinct names for ports in /proc/interrupts

Currently all interrupts assigned to AHCI ports show up in
'/proc/interrupts' as 'ahci'. This fix adds port numbers as
suffixes and hence makes the descriptions distinct.

Reported-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index b830e6c..05adf29 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -306,6 +306,7 @@
 	int			fbs_last_dev;	/* save FBS.DEV of last FIS */
 	/* enclosure management info per PM slot */
 	struct ahci_em_priv	em_priv[EM_MAX_SLOTS];
+	char			*irq_desc;	/* desc in /proc/interrupts */
 };
 
 struct ahci_host_priv {