ASoC: twl6040: Only set the bias_level once in twl6040_resume()

No need to set the bias_level twice to _STANDBY - since this is the only
state the device could be at suspend time. The driver do not support
idle_bias_off yet.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>