usb : usb_kbd : Populating 'priv' member of USB keyboard device_t structure

This patch populates the 'priv' field of the USB keyboard device_t
structure. The 'priv' field is populated with the address of the
'struct usb_device' structure that represents the USB device.

The 'priv' field can then be used in the 'usb_event_poll' function to
determine the USB device that requires to be polled. An
example of its usage in 'usb_event_poll' function is as below.

	device_t *dev;
	struct usb_device *usb_kbd_dev;

	<snip>

	dev = device_get_by_name("usbkbd");
	usb_kbd_dev = (struct usb_device *)dev->priv;
	iface = &usb_kbd_dev->config.if_desc[0];

Signed-off-by: Thomas Abraham <t-abraham@ti.com>
Signed-off-by: Remy Bohmer <linux@bohmer.net>
diff --git a/common/usb_kbd.c b/common/usb_kbd.c
index 89e6ee7..e0d006c 100644
--- a/common/usb_kbd.c
+++ b/common/usb_kbd.c
@@ -183,6 +183,7 @@
 				usb_kbd_dev.puts = NULL;
 				usb_kbd_dev.getc = usb_kbd_getc;
 				usb_kbd_dev.tstc = usb_kbd_testc;
+				usb_kbd_dev.priv = (void *)dev;
 				error = device_register (&usb_kbd_dev);
 				if(error==0) {
 					/* check if this is the standard input device */