sdm_del_channel() function
Delete the Sigma Delta channel
Arguments
chan
SDM channel created by `sdm_new_channel`
Return value
- ESP_OK: Delete the SDM channel successfully - ESP_ERR_INVALID_ARG: Delete the SDM channel failed because of invalid argument - ESP_ERR_INVALID_STATE: Delete the SDM channel failed because the channel is not in init state - ESP_FAIL: Delete the SDM channel failed because of other error