iwlwifi: mvm: use CHECKSUM_COMPLETE

On newer hardware, we have the full checksum, so use it to report
CHECKSUM_COMPLETE and avoid the protocol specific hardware parsing.

Note that the hardware already parses/removes the SNAP header, so
we actually literally get what we need to report to the stack, as
we're expected to checksum everything after the L2 header (which
is translated/added by 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.20200926002540.869e829c815d.I70f374865b0acafc675a8d7959912eeaeb595acf@changeid


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