iwlwifi: mvm: rs: fix search cycle rules

We should explore all possible columns when searching to be
as resilient as possible to changing conditions. This fixes
for example a scenario where even after a sudden creation of
rssi difference between the 2 antennas we would keep doing MIMO
at a low rate instead of switching to SISO at a higher rate using
the better antenna which was the optimal configuration.

Signed-off-by: Eyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>