qcacld-3.0: Fix infinite for loop in wlansap_update_csa_channel_params
In wlansap_update_csa_channel_params if channel is not present in
op class table the for loop become infinite.
Add check to break the loop if BW is 20 and still entry is not found
in op class table.
Change-Id: I6ef6bc138a8df0e18b54bd16a47eba23b437616d
CRs-Fixed: 2373915