mfd: sta2x11-mfd: Add myself to copyright

Signed-off-by: Davide Ciminaghi <ciminaghi@gnudd.com>
Acked-by: Alessandro Rubini <rubini@gnudd.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/sta2x11-mfd.c

 /*
  * Copyright (c) 2009-2011 Wind River Systems, Inc.
- * Copyright (c) 2011 ST Microelectronics (Alessandro Rubini)
+ * Copyright (c) 2011 ST Microelectronics (Alessandro Rubini, Davide Ciminaghi)
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as