ASoC: rsnd: SSI PIO adjust to 24bit mode

commit 90431eb4 ("ASoC: rsnd: don't use PDTA bit for 24bit on SSI")
fixups 24bit mode data alignment, but PIO was not cared.
This patch fixes PIO mode 24bit data alignment

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