iwlwifi: rs: set RTS protection for all non legacy rates

This helps with congested environments reducing the conflict cost to
RTS retries only, instead of the entire BA packet.

Signed-off-by: Mordechay Goodstein <mordechay.goodstein@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200928121852.da97d87d7adf.If06301d4660b14e459195a15831b069b9f6c5e3c@changeid


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