iwlwifi: mvm: set inactivity timeouts also for PS-poll

Code tried to avoid setting ACs for PS-poll by an early return.
However as a result the timeouts weren't set as well.

Inactivity timeout of zero means we will always try to go back to
sleep immediately after moving to AM, which doesn't make much sense,
and isn't supported by FW.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20211017165728.dda7f6ba0b22.Ia107bfe496b84e8a2edb33d9f39a5d2b56ed63f7@changeid


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