mac80211: support Rx timestamp calculation for all preamble types

mac80211: support Rx timestamp calculation for all preamble types

Add support for calculating the Rx timestamp for HE frames.
Since now all frame types are supported, allow setting the Rx
timestamp regardless of the frame type.

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.20201206145305.4786559af475.Ia54486bb0a12e5351f9d5c60ef6fcda7c9e7141c@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>