staging: olpc: Add <linux/delay.h>

 The olpc dcon xo1 driver uses udelay() without including <linux/delay.h>.

 This patch adds it.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Andres Salomon <dilinger@queued.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>