iw: scan: add extension tag parsing

HE IEs are part of the extension tag (ID 255).

Signed-off-by: Brian Norris <briannorris@chromium.org>
Link: https://lore.kernel.org/r/20201118033936.3667788-2-briannorris@chromium.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
1 file changed