iwlwifi: mvm: do not turn on RX_FLAG_AMSDU_MORE

This flag is used for mac80211 reordering. As we do reordering
ourselves, turning it on is misleading and pointless.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>