ASoC: rsnd: tidyup return value of rsnd_get_adinr_bit()

Renesas sound driver has rsnd_get_adinr_bit/chan() functions.
It is assuming _bit() returns ADINR :: OTBL,
and _chan() returns ADINR :: CHNUM.
Current _bit() returns both OTBL and CHNUM. This patch fixup it.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>