qcacmn: Add dfs tgt API to set Sub Channel Marking

Introduce dfs_tgt API to send the WMI command to enable/disable
"Subchannel Marking" in Firmware (only in  Full Offload)

Change-Id: If739409521c8704b612e52dfc8ed6b86ffe32bca
CRs-Fixed: 2334258
6 files changed