qcacld-2.0: Add support for private ioctls for TDLS Offchannel

Add support for private ioctls in the TDLS Offchannel to
set channel num and enable disable offchannel as needed
by sigma-dut to pass the certification.

Change-Id: I94aebedcf6d3f8b4deb9b2e77ff9f5822aab0728
CRs-Fixed: 2175359