BSS coloring: BSS Color Change Announcement element generation

BSS coloring: BSS Color Change Announcement element generation

This information element is similar to the CSA one. It contains a
counter and the target color. Once the counter expired, the change to
the new color happens.

Just note the current implementation is based on CCA counter attributes
that only take Beacon and Probe Response framesinto account.
(Re)Association Response frames do not currently have kernel APIs to
decrement the CCA counter since mediatek mcu firmware does not support
it yet and it will be added in future firmware release.

Tested-by: Peter Chiu <chui-hao.chiu@mediatek.com>
Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>