iwlwifi: mvm: handle RX checksum on Bz devices

On Bz devices, the hardware checksums including the SNAP header,
starting directly after the MAC header, so we don't need the
extra checks and can just pass the checksum to mac80211.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20211219121514.8ef59da4e05e.Ide87c2dc8fa08eae55c013a625f4ece5184b1b63@changeid


Signed-off-by: Luca Coelho <luciano.coelho@intel.com>