ieee80211: update reduced neighbor report TBTT info length

A new field (20MHz PSD - 1 byte) was added to the RNR TBTT info field.
Adjust the expected TBTT info length accordingly.

Signed-off-by: Avraham Stern <avraham.stern@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20201129172929.b503adccce6a.Ie684e1d3039c111bf2d521bf762aaec3f7a24d2e@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>