wifi: iwlwifi: mvm: reduce maximum RX A-MPDU size

Since 1024 isn't being tested right now, allow only 512
for now.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230830112059.6e80366716ad.I19022084ac978b9960b12b205c052a83ab141203@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>