ASoC: pcm1789: Make pcm1789_common_exit() return void

This function returns zero unconditionally, so there isn't any benefit
of returning a value. Make it return void to be able to see at a glance
that the return value of pcm1789_i2c_remove() is always zero.

This patch is a preparation for making i2c remove callbacks return void.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20220425193023.61046-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>

ASoC: codecs: Add support for PCM1789

Add Texas Instruments's PCM1789 DAC support.
It is a simple DAC and does not have many registers.

One particularity about this DAC is that the clocks must be
always enabled. Also, an entire software reset is necessary
while starting to play a sound otherwise, the clocks are not
synchronized (so the DAC is not able to send data).

Signed-off-by: Mylène Josserand <mylene.josserand@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>