qcacmn: Clear legacy channel ID usage

1) Remove the definition of plm_ch_list from
   struct plm_req_params and add plm_ch_freq_list
   into the same struct given frequencies will be
   used directly before passing WMI command to
   firmware.

2) Remove redundant channel frequency list from the
   following API functions' parameters:

   send_plm_start_cmd
   wmi_unified_plm_start_cmd
   send_plm_start_cmd_tlv

Change-Id: I982412076b422356037d9bbfa2077affd1056189
CRs-Fixed: 2560085
5 files changed