iw: update freq to chan mappings for 6GHz band per IEEE P802.11ax/D6.1

iw: update freq to chan mappings for 6GHz band per IEEE P802.11ax/D6.1

This fixes dfferences in 6GHz frequencies which were updated in
IEEE P802.11ax/D6.1.

Also sync 60GHz band channel to freq mapping with kernel.

Fixes: 43789196 ("iw: sync frequency to channel mapping with kernel for 6GHz band")
Signed-off-by: Pradeep Kumar Chitrapu <pradeepc@codeaurora.org>
Link: https://lore.kernel.org/r/20200622063906.24957-1-pradeepc@codeaurora.org
[remove MHZ_TO_KHZ conversion???]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>