qcacmn: Fix channel_map NULL

Initialize channel_map to "us" at regulatory init.
Use NUM_6GHZ_CHANNELS to get 6Ghz channel numbers
instead of MAX_6GHZ_CHANNEL.

Change-Id: Ifed996c1a528c8a3c0a29d3959f17dff6d298193
CRs-Fixed: 2949971

umac/regulatory/dispatcher/src/wlan_reg_services_api.c

@@ -341,7 +341,7 @@ QDF_STATUS wlan_regulatory_init(void)
 		reg_err("failed to register reg psoc obj create handler");
 		goto unreg_pdev_create;
 	}
-
+	channel_map = channel_map_global;
 	reg_debug("regulatory handlers registered with obj mgr");
 
 	return status;