qcacmn: Export wlan_reg_freq_width_to_chan_op_class API

Export the wlan_reg_freq_width_to_chan_op_class() API.
API will be used by Change Id I69106463a587bf0717dbce3067b69bb7272ca976.

Change-Id: I3c751ccd6499bc0de48bdbb6086cf3ec7c8e9b88
CRs-Fixed: 3443845

umac/regulatory/dispatcher/src/wlan_reg_services_api.c

@@ -1405,6 +1405,8 @@ void wlan_reg_freq_width_to_chan_op_class(struct wlan_objmgr_pdev *pdev,
 					       chan_num);
 }
 
+qdf_export_symbol(wlan_reg_freq_width_to_chan_op_class);
+
 void wlan_reg_freq_width_to_chan_op_class_auto(struct wlan_objmgr_pdev *pdev,
 					       qdf_freq_t freq,
 					       uint16_t chan_width,