[PATCH] xhci: Fix compile error when CONFIG_PM=n

[Sarah Sharp <sarah.a.sharp@linux.intel.com>]

Fix this error when CONFIG_PM is not enabled:

drivers/usb/host/xhci.c:675: error: implicit declaration of function 'usb_root_hub_lost_power'

Wrap xhci_suspend() and xhci_resume() into an ifdef CONFIG_PM, along with
the functions that only they call -- xhci_save_registers() and
xhci_restore_registers().

Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
---
 drivers/usb/host/xhci.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 33d0034..9dc5be5 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -551,6 +551,7 @@ void xhci_shutdown(struct usb_hcd *hcd)
 		    xhci_readl(xhci, &xhci->op_regs->status));
 }
 
+#ifdef CONFIG_PM
 static void xhci_save_registers(struct xhci_hcd *xhci)
 {
 	xhci->s3.command = xhci_readl(xhci, &xhci->op_regs->command);
@@ -761,6 +762,13 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
 	return 0;
 }
 
+#else
+
+#define	xhci_suspend	NULL
+#define	xhci_resume	NULL
+
+#endif	/* CONFIG_PM */
+
 /*-------------------------------------------------------------------------*/
 
 /**
-- 
1.6.3.3