Add Support for JustBoom Audio boards

Add Support for JustBoom Audio boards

justboom-dac: Adjust for ALSA API change

As of 4.4, snd_soc_limit_volume now takes a struct snd_soc_card *
rather than a struct snd_soc_codec *.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>
ASoC: justboom-dac: fix S24_LE format

Remove set_bclk_ratio call so 24-bit data is transmitted in
24 bclk cycles.

Also remove hw_params as it's no longer needed.

Signed-off-by: Matthias Reichl <hias@horus.com>
ASoC: justboom-dac: use modern dai_link style

Signed-off-by: Matthias Reichl <hias@horus.com>