Change in coreboot[master]: Makefile.inc: Update the master header pointer in a separate target

[Arthur Heymans (Code Review)]

Attention is currently required from: Arthur Heymans, Martin Roth, Julius Werner, Yu-Ping Wu.
Arthur Heymans has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/59132 )

Change subject: Makefile.inc: Update the master header pointer in a separate target
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Patch Set 4:

(1 comment)

Commit Message:

https://review.coreboot.org/c/coreboot/+/59132/comment/eefba47d_3d492b13 
PS4, Line 9: The makefiles don't like cbfs file names with spaces
> > I'm good with how it's done now, but honestly, this seems odd to me.  We should be able to escape it and make it work.  maybe '\ ' so that after the 1st evaluation we get '\ ' presented to the shell?
>
> Thanks, I'll try that.

That didn't work sadly...