ASoC: fsl_sai: fix bit order for DSD format

The DSD little endian format requires the msb first, because oldest bit
is in msb.
found this issue by testing with pipewire.

Fixes: c111c2dd ("ASoC: fsl_sai: Add PDM daifmt support")
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Link: https://patch.msgid.link/20251023064538.368850-2-shengjiu.wang@nxp.com


Signed-off-by: Mark Brown <broonie@kernel.org>