[U-Boot] [IMPORTANT NOTE] License handling

[Masahiro Yamada]

Hello, Wolfgang.


> - New files being added to U-Boot should no longer include a
>   multi-line license header; instead, they shall contain a single line
>   Unique Lincense Identifier, i. e. a line like this:
> 
>   	SPDX-License-Identifier:        GPL-2.0+


I have a question about this.
Does this rule apply to files imported from other projects?

For example, when adding files that originate from the Linux Kernel
with modification for U-Boot, should we replace the legacy license
block with SPDX-License-Identifer?
Or can we keep the license block untouched?

Best Regards
Masahiro Yamada