wifi: iwlwifi: mvm: avoid always prefering single-link

The new link selection algorithm uses defaults values for BSS load if
the BSS Load element was not published by the AP.
For 6 GHz, that value is 0. So if the best link is 6 GHz, the EMLSR
grade to always be equal to the grade of the best link,
and then the best link grade is getting a bonus of 10 percent, meaning
that we will never activate EMLSR.
Change the logic to not give a bonus for the best link.

Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240505091420.4614e6891dbd.Ie40eae0dd99d82ba60dea5b6dbcd42dcdf16b90d@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>