iwlwifi: mvm: rs: fix RTS protection being set indefinitely

RTS protection was turned on once aggregation was enabled but it
was never turned off. Remove turning on RTS protection in the LQ command
completely as TX_CMD_FLG_PROT_REQUIRE gets set in iwl_mvm_set_tx_cmd
for every Tx which is part of an aggregation. This would already cause
RTS protection to be used during aggregations.

Signed-off-by: Eyal Shapira <eyal@wizery.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>