[U-Boot] dual licensed files

[Wolfgang Denk <wd@denx.de>]

Dear Roger,

In message <047701ce8a46$bcc78820$36569860$@bufferoverflow.ch> you wrote:
> Thank you Wolfgang for simplifying license handling!

You are welcome!

> What about dual licensed files? What do you prefer?
> 
> SPDX-License-Identifier:        GPL-2.0+
> SPDX-License-Identifier:        BSD-2-Clause

This was my initial idea when I started thinking about this, but then
I realized that there were a few files that had (by accident) both
GPL-2.0+ and GPL-2.0 license headers (separated by a larger text
block, so it was not obvious at first glance), so my first attempts of
automatic editing would generate two (here incompatible) License-ID
entries.

Because of this I think there should be exactly one License-ID entry
in any file.  So for dual-licensed files the entry should list the
license IDs in a single entry.

> SPDX-License-Identifier:        GPL-2.0+, BSD-2-Clause
> 	Other seperator?

Yes, please let's just use white space for separation; this is easier
to parse by simple (shell) scripts.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
"I've seen it. It's rubbish."          - Marvin the Paranoid Android