wifi: iwlwifi: mvm: don't always disable EMLSR due to BT coex

2.4 GHz/LB (low band) link can't be used in an EMLSR links pair when
BT is on. But EMLSR is still allowed for a pair of links which none of
them operates in LB.
In the existing code, EMLSR will always be disabled if one of the
usable links is in LB (and BT is on).
Move this check to the code that verifies a specific pair of links,
and only if one of these links operates on LB - disable EMLSR.

Fixes: 10159a45

 ("wifi: iwlwifi: disable eSR when BT is active")
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240416134215.2841006b5cc4.I45ffd583f593daa950322852ceb9454cbf497e24@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>