TDM support needs to use constraint_channels.
This patch renames current constraint to constraint_rates for it.
This is prepare for TDM support.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87a6d0p9l7.wl-kuninori.morimoto.gx@renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>