BACKPORT: nl80211: add handling for BSS color

This patch adds the attributes, policy and parsing code to allow userland
to send the info about the BSS coloring settings to the kernel.

Bug: 154782456
Signed-off-by: John Crispin <john@phrozen.org>
Link: https://lore.kernel.org/r/20191217141921.8114-1-john@phrozen.org


[johannes: remove the strict policy parsing, that was a misunderstanding]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Change-Id: Ib24133d6825ef455819f697de6d9d67c856c315e
(cherry picked from commit 5c5e52d1bb962510fecdc1ebecdde89694d1b223)
Signed-off-by: Vamsi Krishna <vamsin@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>