mtd: onenand: Get rid of comments giving the file path inside the file itself

Some files add a comment giving the path of the file inside the Linux
tree, which is pretty useless since the reader had to find the file to
open it.

Getting rid of these comments will also allow us to easily move these
files around when needed.
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

drivers/mtd/onenand/generic.c

 /*
- *  linux/drivers/mtd/onenand/generic.c
- *
  *  Copyright (c) 2005 Samsung Electronics
  *  Kyungmin Park <kyungmin.park@samsung.com>
  *

drivers/mtd/onenand/omap2.c

 /*
- *  linux/drivers/mtd/onenand/omap2.c
- *
  *  OneNAND driver for OMAP2 / OMAP3
  *
  *  Copyright © 2005-2006 Nokia Corporation

drivers/mtd/onenand/onenand_base.c

 /*
- *  linux/drivers/mtd/onenand/onenand_base.c
- *
  *  Copyright © 2005-2009 Samsung Electronics
  *  Copyright © 2007 Nokia Corporation
  *

drivers/mtd/onenand/onenand_bbt.c

 // SPDX-License-Identifier: GPL-2.0
 /*
- *  linux/drivers/mtd/onenand/onenand_bbt.c
- *
  *  Bad Block Table support for the OneNAND driver
  *
  *  Copyright(c) 2005 Samsung Electronics