util/nvramtool: Remove "this file is part of" lines

As requested by Stefan.

For nvramtool some of these lines are part of a paragraph of fluff,
so manual processing was easier than adapting the script used for
the rest of the tree.

Change-Id: Id52c4c264cded0582a97da131b695a046cbd67c6
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41195
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Reviewed-by: Martin Roth <martinroth@google.com>

util/nvramtool/reg_expr.c

@@ -1,10 +1,6 @@
 /*****************************************************************************\
  * reg_expr.c
  *****************************************************************************
- *  This file is part of nvramtool, a utility for reading/writing coreboot
- *  parameters and displaying information from the coreboot table.
- *  For details, see https://coreboot.org/nvramtool.
- *
  *  Please also read the file DISCLAIMER which is included in this software
  *  distribution.
  *