Fix 160 MHz opclass channel to frequency conversion
This needs to allow all 20 MHz channel numbers to be converted even
though the Annex E table lists only channel _center_ frequencies 50 and
114. Neighbor Report (see IEEE Std 802.11-2016, 9.4.2.37 Neighbor Report
element) uses Channel Number field with "last known primary channel of
the AP" which refers to the 20 MHz channel and not the channel center
frequency.
Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>