BACKPORT: cfg80211: reject HT/VHT capabilities on 6 GHz band

On the 6 GHz band, HE should be used, but without any direct HT/VHT
capabilities, instead the HE 6 GHz band capabilities will capture
the relevant information. Reject HT/VHT capabilities here.

Bug: 163110886

Link: https://lore.kernel.org/r/20200528213443.bfe89c35459a.Ibba5e066fa0087fd49d13cfee89d196ea0c68ae2@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>
(cherry picked from commit 461ce35d)
Change-Id: Ife9644cc1c2533255863593861a3e79eb5dac56b
Signed-off-by: Vamsi Krishna <vamsin@codeaurora.org>