drivers: wifi: Handle regulatory domain change

There is no handler, but this is still needed to avoid the "no callback
registered" warning.

Signed-off-by: Chaitanya Tata <Chaitanya.Tata@nordicsemi.no>

drivers/wifi/nrf700x/osal/fw_if/umac_if/src/event.c

@@ -505,6 +505,9 @@ static enum wifi_nrf_status umac_event_ctrl_process(struct wifi_nrf_fmac_dev_ctx
 					      __func__,
 					      umac_hdr->cmd_evnt);
 		break;
+	case NRF_WIFI_UMAC_EVENT_REG_CHANGE:
+		/* TODO: Inform the user space about the regulatory change */
+		break;
 #endif /* CONFIG_WPA_SUPP */
 	default:
 		wifi_nrf_osal_log_err(fmac_dev_ctx->fpriv->opriv,