ASoC: omap-mcpdm: Set 24msbits constraint

McPDM internal FIFO is 24 bit wide. From the 32 bit sample
8 bit is discarded. Let application know about this
via msbits constraint.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/omap/omap-mcpdm.c

@@ -419,12 +419,14 @@ static struct snd_soc_dai_driver omap_mcpdm_dai = {
 		.channels_max = 5,
 		.rates = OMAP_MCPDM_RATES,
 		.formats = OMAP_MCPDM_FORMATS,
+		.sig_bits = 24,
 	},
 	.capture = {
 		.channels_min = 1,
 		.channels_max = 3,
 		.rates = OMAP_MCPDM_RATES,
 		.formats = OMAP_MCPDM_FORMATS,
+		.sig_bits = 24,
 	},
 	.ops = &omap_mcpdm_dai_ops,
 };