scripts: get_abi.pl: detect softlinks

scripts: get_abi.pl: detect softlinks

The way sysfs works is that the same leave may be present under
/sys/devices, /sys/bus and /sys/class, etc, linked via soft
symlinks.

To make it harder to parse, the ABI definition usually refers
only to one of those locations.

So, improve the logic in order to retrieve the symlinks.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/77c49f7d158d88e17f18d40652b75cdde9e179eb.1631957565.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>