ASoC: rockchip: rockchip_sai: Set slot width for non-TDM mode

ASoC: rockchip: rockchip_sai: Set slot width for non-TDM mode

Currently the slot width in non-TDM mode is always kept at the POR value
of 32 bits, regardless of the sample width, which doesn't work well for
some codecs such as NAU8822.

Set the slot width according to the sample width in non-TDM mode, which
is what other CPU DAI drivers do.

Tested on the following RK3576 configurations:
- SAI2 + NAU8822 (codec as the clock master), custom board
- SAI1 + ES8388 (codec as the clock master), RK3576 EVB1
- SAI2 + RT5616 (SAI as the clock master), FriendlyElec NanoPi M5

NAU8822 didn't work prior to this patch but works after the patch. Other
two configurations work both before and after the patch.

Fixes: cc78d1eaabad ("ASoC: rockchip: add Serial Audio Interface (SAI) driver")
Signed-off-by: Alexey Charkov <alchark@flipper.net>
Tested-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Link: https://patch.msgid.link/20260318-sai-slot-width-v1-1-1f68186f71e3@flipper.net
Signed-off-by: Mark Brown <broonie@kernel.org>