wl12xx: add missing copyright notice

The wl12xx_platform_data.c file did not have a proper copyright
notice.
Signed-off-by: Luciano Coelho <coelho@ti.com>

drivers/net/wireless/wl12xx/wl12xx_platform_data.c

+/*
+ * This file is part of wl12xx
+ *
+ * Copyright (C) 2010-2011 Texas Instruments, Inc.
+ *
+ * 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 published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
 #include <linux/module.h>
 #include <linux/err.h>
 #include <linux/wl12xx.h>