iwlwifi: mvm: use designated initialization for some arrays

rs_ht_to_legacy and ant_toggle_lookup are arrays that
represent some state-machine. initialize them explicitly
with designated initialization to make them more clear
and avoid errors.

Signed-off-by: Eliad Peller <eliad@wizery.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>