qcacmn: Get opclass from freq and width given a country code

Add the API wlan_reg_get_opclass_from_freq_width, to give country_iso,
channel frequency, channel width and behaviour limit as input, and get
the operating class as output.

Change-Id: I96c39119ab855d10965b2603e8b15c21699daa68
CRs-Fixed: 2583789
4 files changed