iwlwifi: mvm: disable RX-diversity in powersave

Just like we have default SMPS mode as dynamic in powersave,
we should not enable RX-diversity in powersave, to reduce
power consumption when connected to a non-MIMO AP.

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.20211017113927.fc896bc5cdaa.I1d11da71b8a5cbe921a37058d5f578f1b14a2023@changeid


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