treewide: Remove trailing whitespace

Remove trailing whitespace in files that aren't typically checked.

Signed-off-by: Martin Roth <martin@coreboot.org>
Change-Id: I8dfffbdeaadfa694fef0404719643803df601065
Reviewed-on: https://review.coreboot.org/c/coreboot/+/50704
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

Documentation/coding_style.md

@@ -530,7 +530,7 @@ than desirable (in fact, they are worse than random typing - an infinite
 number of monkeys typing into GNU emacs would never make a good program).
 
 So, you can either get rid of GNU emacs, or change it to use saner values.
-To do the latter, you can stick the following in your .emacs file: 
+To do the latter, you can stick the following in your .emacs file:
 
 ```lisp
 (defun c-lineup-arglist-tabs-only (ignored)