usb: ehci-omap: fix compilation warning

Fixes below compilation warning:
drivers/usb/host/ehci-hcd.c:425:
	warning: 'ehci_port_power' defined but not used

Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/host/ehci-omap.c b/drivers/usb/host/ehci-omap.c
index 40a8583..711332e 100644
--- a/drivers/usb/host/ehci-omap.c
+++ b/drivers/usb/host/ehci-omap.c
@@ -659,6 +659,9 @@
 		goto err_add_hcd;
 	}
 
+	/* root ports should always stay powered */
+	ehci_port_power(omap->ehci, 1);
+
 	return 0;
 
 err_add_hcd: