qcacld-3.0: Fix unknown phymode in vdev start

If gDot11Mode=1 is set to INI, DUT STA will be failed to
connect to 5G AP due to "unknown phymode" included in
vdev start.
Correct the driver to use freq API to identify 5G band
BSS instead of channel API.
And the change forces 11ax mode for 6ghz bss.

Change-Id: I692fa744756490e7125ccd5fd82c15febc19ce68
CRs-Fixed: 2594048
1 file changed