clang-format: Extend the for_each list with tools/

clang-format: Extend the for_each list with tools/

Add tools/ to the shell fragment generating the for_each list and update
it.  This is useful to format files in the tools directory (e.g.
selftests) with the same coding style as the kernel.

Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Tom Rix <trix@redhat.com>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Link: https://lore.kernel.org/r/20220506160106.522341-2-mic@digikod.net
[Reworded and rebased on top of previous commits]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>