PCI: add power-state name strings

This patch (as1235) adds an array of PCI power-state names, together
with a simple inline accessor routine.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 72698d8..8e366bb 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -124,6 +124,14 @@
 #define PCI_UNKNOWN	((pci_power_t __force) 5)
 #define PCI_POWER_ERROR	((pci_power_t __force) -1)
 
+/* Remember to update this when the list above changes! */
+extern const char *pci_power_names[];
+
+static inline const char *pci_power_name(pci_power_t state)
+{
+	return pci_power_names[1 + (int) state];
+}
+
 #define PCI_PM_D2_DELAY	200
 #define PCI_PM_D3_WAIT	10
 #define PCI_PM_BUS_WAIT	50