[S] Change in coreboot[main]: Makefile: update clean-symlink target

[Martin Roth (Code Review)]

Attention is currently required from: Martin L Roth, Maximilian Brune.

Martin Roth has uploaded a new patch set (#2) to the change originally created by Martin L Roth. ( https://review.coreboot.org/c/coreboot/+/83124?usp=email )

Change subject: Makefile: update clean-symlink target
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Makefile: update clean-symlink target

This almost completely replaces the original clean-symlink target to
remove links from site-local into the coreboot tree. Changes include:

- Symbolic links removed are based on the EXTERNAL_SYMLINKS value of
symlink.txt files under site-local.
- Verify that there are site-local symlink.txt files to work on before
doing anything.
- Verify that the symlink.txt files reference links inside the coreboot
directory.
- Print out whether or not there are remaining symbolic links in the
tree.

Signed-off-by: Martin Roth 
Change-Id: Ife0e7cf1b856b7394cd5e1de9b35856bd984663c
---
M Makefile
1 file changed, 29 insertions(+), 5 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/24/83124/2