iw: support HE rate configuration in 6 GHz band
iw: support HE rate configuration in 6 GHz band

Allow HE-MCS, HE-GI, HE-LTF in 6 GHz band as well and allow only
MCS rates in 6 GHz.

Signed-off-by: Rajkumar Manoharan <58b9aefd02b38fd9636344325c091015d8dc872b@codeaurora.org>
Link: https://lore.kernel.org/r/1601431538-6621-2-git-send-email-58b9aefd02b38fd9636344325c091015d8dc872b@codeaurora.org
Signed-off-by: Johannes Berg <bff32994ff0f8d048f262a8388145a71b6071bfe@intel.com>

greearb/iw-ct,greearb/iw-ct