[U-Boot] Lots of SPDX-License Identifer have a trailing space

Hello Wolfgang,

I noticed many of SPDX-License blocks have a trailing space after "GPL-2.0+".

For example, arch/arm/cpu/arm1136/start.S

* * SPDX-License-Identifier: GPL-2.0+[A Trailing Space] */

Is this space the one intentinally added? (If not, I can send a patch to fix it.)

I am not sure whether I should precisely copy and paste SPDX indentifier or drop a trailing space when I add a new source file.

Best Regards Masahiro Yamada