wifi: iwlwifi: mvm: don't recompute EMLSR mode in can_activate_links

wifi: iwlwifi: mvm: don't recompute EMLSR mode in can_activate_links

mac80211 invokes the driver callback drv_can_activate_links() from
ieee80211_set_active_links to verify it can activate the desired link
combination.
However, ieee80211_set_active_links is called with more than one link in
2 cases:
- After driver's link selection decided to enter EMLSR
- From debugfs, for testing purposes.
For both cases there is no need to recompute all the considerations
determining whether to activate EMLSR.
Instead, only check if the vif is not blocked for EMLSR.

Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Link: https://msgid.link/20240416134215.202cf5a9ef2c.I65e4698b730a8652ad8d1c01420aabb41a1d04fd@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>