qcacmn: resolve race issue accessing pm_conc_connection_list

While function policy_mgr_set_pcl_for_existing_combo posts event
SIR_HAL_PDEV_SET_PCL_TO_FW and before restores pm_conc_connection_list,
the function policy_mgr_get_valid_chan_weights is invoking and
accessing pm_conc_connection_list then race happens.

To resolve the issue, restore the pm_conc_connection_list before
calling SME function.

CRs-Fixed: 2370113
Change-Id: I8b30dc5084c4aae4bcc4b3b350d19c8be89338a9