qcacld-3.0: Update HDD channel validation for frequency

Due to channel number duplication with introduction of 6Ghz band
support update hdd channel validation function to check channel
frequency instead of channel number. Also remove channel references
in start_bss path.

Change-Id: I5f37524b71a2b224ca79b0f67f871e50523e16be
CRs-fixed: 2545103
3 files changed