jep106: add SPDX tag and JEDEC copyright

As a follow-up of talks between JEDEC and STMicroelectronics,
JEDEC agrees to let OpenOCD project including the manufacturer's
identification code list extracted from JEDEC JEP106 document and
to let OpenOCD being updated regularly using the future JEDEC
JEP106 document versions. JEDEC requires OpenOCD to report the
origin of the JEDEC JEP106 manufacturer's identification code list
together with the JEDEC copyright.

As agreed with JEDEC, add in the file jep106.inc:
- the SPDX tag with the GPL license of the OpenOCD project;
- the JEDEC copyright;
- the text provided by JEDEC reporting the origin of the JEDEC
  JEP106 manufacturer's identification code list.

While there:
- add a line reporting the version of the JEP106 document that was
  used for the current code list extraction;
- remove the obsolete comment, as the script for extraction is not
  working anymore; keep the script as example.

Change-Id: Iaa76716db14e15ffca04fcf7d8c27bb85a27ba10
Signed-off-by: Antonio Borneo <antonio.borneo@st.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/7147
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

src/helper/jep106.inc

@@ -1,9 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
 /*
- * Should be autogenerated with update_jep106.pl but latest
- * file from JEDEC is only available in PDF form. The PDF
- * also breaks the pdftotext flow due to embedded watermarks.
- * Created with a mix of scripts and manual editing.
+ * The manufacturer's standard identification code list appears in JEP106.
+ * Copyright (c) 2022 JEDEC. All rights reserved.
+ *
+ * JEP106 is regularly updated. For the current manufacturer's standard
+ * identification code list, please visit the JEDEC website at www.jedec.org .
  */
+
+/* This file is aligned to revision JEP106BC February 2021. */
+
 [0][0x01 - 1] = "AMD",
 [0][0x02 - 1] = "AMI",
 [0][0x03 - 1] = "Fairchild",