With P0 R29, Bit2 set the I2S clocks will be running when the DAC/ADC is
powered down, but still the codec need to be powered up by needing at least
one complete DAPM path for the stream.

If the AIF is not needed (analog loopback for example) the I2S clocks will
not run as they are not needed.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Suggested-by: Stefan Müller-Klieser <s.mueller-klieser@phytec.de>
Signed-off-by: Mark Brown <broonie@kernel.org>