This patch syncs naming rule.

 - xxx_rates;
 + xxx_rate;

 - xxx_samplebits;
 + xxx_sample_bits;
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87o8hqoli4.wl-kuninori.morimoto.gx@renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>