Fixed firmware cleanup script

[lslezak]

Problem

• See Missing wifi drivers (T14s) Qualcomm #1756
• Some firmware files were missing in the Live ISO

Solution

There were basically two problems:

1. Few kernel modules use wildcards to specify the firmware files, e.g. ath11k/WCN6855/hw2.1/*. That was not supported by the script, it expected only individual file names referenced by drivers.
2. Some firmware files use symlinks, e.g. the driver refers to foo.bin file but in some cases it is actually a symlink pointing to foo-1.0.bin. The script then deleted the foo-1.0.bin file as it looked like not used by drivers. The result was a dangling symlink and a missing firmware file.

Both issues were fixed. The glob patterns are evaluated using the Dir.glob function and if the referenced file is a symlink then it also keeps the target file where the symlink points to.

Testing

• Tested manually, the firmware for Atheros cards is now present
• I compared the result with installation-images and now we basically include the same firmware as installation-images do in the classic Tumbleweed installation
• The ISO size increased just by ~13MB, fortunately not that much...