ASoC: mediatek: mt8188: DPCM used FE and BE merged parameters

To ensure that DPCM takes into account the backend hardware limitations
when user space queries the hw_params of a device, we need to add
dpcm_merged_format, dpcm_merged_chan, and dpcm_merged_rate to the FE
dai_links.

This patch includes only stereo FE dai_links, since multi-channel FEs
may be reserved for specific purposes. Therefore, it may not be
appropriate to consider BE conditions.
Signed-off-by: Trevor Wu <trevor.wu@mediatek.com>
Link: https://lore.kernel.org/r/20230706064123.29790-1-trevor.wu@mediatek.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/mediatek/mt8188/mt8188-mt6359.c

@@ -723,6 +723,9 @@ static struct snd_soc_dai_link mt8188_mt6359_dai_links[] = {
 		},
 		.dynamic = 1,
 		.dpcm_playback = 1,
+		.dpcm_merged_chan = 1,
+		.dpcm_merged_rate = 1,
+		.dpcm_merged_format = 1,
 		SND_SOC_DAILINK_REG(playback2),
 	},
 	[DAI_LINK_DL3_FE] = {
@@ -734,6 +737,9 @@ static struct snd_soc_dai_link mt8188_mt6359_dai_links[] = {
 		},
 		.dynamic = 1,
 		.dpcm_playback = 1,
+		.dpcm_merged_chan = 1,
+		.dpcm_merged_rate = 1,
+		.dpcm_merged_format = 1,
 		SND_SOC_DAILINK_REG(playback3),
 	},
 	[DAI_LINK_DL6_FE] = {
@@ -745,6 +751,9 @@ static struct snd_soc_dai_link mt8188_mt6359_dai_links[] = {
 		},
 		.dynamic = 1,
 		.dpcm_playback = 1,
+		.dpcm_merged_chan = 1,
+		.dpcm_merged_rate = 1,
+		.dpcm_merged_format = 1,
 		SND_SOC_DAILINK_REG(playback6),
 	},
 	[DAI_LINK_DL7_FE] = {
@@ -833,6 +842,9 @@ static struct snd_soc_dai_link mt8188_mt6359_dai_links[] = {
 		},
 		.dynamic = 1,
 		.dpcm_capture = 1,
+		.dpcm_merged_chan = 1,
+		.dpcm_merged_rate = 1,
+		.dpcm_merged_format = 1,
 		SND_SOC_DAILINK_REG(capture4),
 	},
 	[DAI_LINK_UL5_FE] = {
@@ -844,6 +856,9 @@ static struct snd_soc_dai_link mt8188_mt6359_dai_links[] = {
 		},
 		.dynamic = 1,
 		.dpcm_capture = 1,
+		.dpcm_merged_chan = 1,
+		.dpcm_merged_rate = 1,
+		.dpcm_merged_format = 1,
 		SND_SOC_DAILINK_REG(capture5),
 	},
 	[DAI_LINK_UL6_FE] = {