iwlwifi: mvm: Always enable the smart FIFO

We previously enabled the smart FIFO (SF) in BSS only after
association.
This cause interrupt latency on P2P on certain devices.
Change the working model to enable the SF all the time and
play with the timeout values based on the association state.
This change was not tested on older firwmares, so make it
happen only on -13.ucode and up.

Signed-off-by: Eran Harary <eran.harary@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>