lib/ubsan.c: Restore Jonas' copyright

During the cleanup of copyright lines, this file was incorrectly changed
to remove the copyright line. It is not originally a part of the
coreboot project, having been pulled in and adapted for use in coreboot.
As such, and with the ISC license specifying that the copyright line
should be maintained, the copyright line has been restored.

See coreboot ticket # 479 for more information.

Signed-off-by: Martin Roth <gaumless@gmail.com>
Change-Id: Ia234cebd0a6d49d03e40c5a57cd346a07f3e4b09
Reviewed-on: https://review.coreboot.org/c/coreboot/+/75343
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-by: David Hendricks <david.hendricks@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Fred Reitberger <reitbergerfred@gmail.com>
Reviewed-by: Felix Singer <service+coreboot-gerrit@felixsinger.de>
Reviewed-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>

src/lib/ubsan.c

@@ -4,6 +4,9 @@
  *
  * Adapted from:
  * https://gitlab.com/sortix/sortix/raw/master/libc/ubsan/ubsan.c
+ *
+ * Copyright (c) 2014, 2015 Jonas 'Sortie' Termansen.
+ *
  */
 
 #include <stdint.h>