PS should not be enabled if an infra AP vif exists in
the interface list. So while recalculating PS,
AP vif type should be taken into account.
Reviewed-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NRajkumar Manoharan <rmanoharan@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>