wifi: iwlwifi: enable 320 MHz on slow PCIe links

Despite not being able to sustain the full 320 MHz throughput
even at MCS 9, enable 320 MHz on slow PCIe links. This may in
some cases result in frames being dropped (on the air) by the
firmware if they cannot be delivered to the host, but it can
still be better to use 320 MHz.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250205145347.1e5356a3b124.I1224023721aaeff8ebcaa47dff88613c7fd0533a@changeid


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