Currently policy_mgr_modify_sap_pcl_for_6G_channels() only find the
first STA or P2P-CLI, then check its channel is 6 GHz or not,
It will lead to different behavior if there is MLO STA which has one
link connected on 6 GHz, sometime PCL modify for 6 GHz channels,
sometime not.
Change to find first 6 GHz STA or P2P-CLI, only if has, continue to
do 6 GHz channels modify.
Change-Id: I96d01ded297fb900f0ea715b75cbdadb9faade3d
CRs-Fixed: 3526650
add0c193f1