ASoC: loongson: make loongson-i2s.o a separate module

An object file should not be linked into multiple modules and/or
vmlinux:

scripts/Makefile.build:221: /home/arnd/arm-soc/sound/soc/loongson/Makefile: loongson_i2s.o is added to multiple modules: snd-soc-loongson-i2s-pci snd-soc-loongson-i2s-plat

Change this one to make it a library module with two exported symbols
that will work in any configuration.

Fixes: ba4c5fa ("ASoC: loongson: Add I2S controller driver as platform device")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patch.msgid.link/20241015150958.2294155-1-arnd@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/loongson/Makefile

@@ -1,10 +1,12 @@
 # SPDX-License-Identifier: GPL-2.0
 #Platform Support
-snd-soc-loongson-i2s-pci-y := loongson_i2s_pci.o loongson_i2s.o loongson_dma.o
-obj-$(CONFIG_SND_SOC_LOONGSON_I2S_PCI) += snd-soc-loongson-i2s-pci.o
+snd-soc-loongson-i2s-pci-y := loongson_i2s_pci.o loongson_dma.o
+obj-$(CONFIG_SND_SOC_LOONGSON_I2S_PCI) += snd-soc-loongson-i2s-pci.o snd-soc-loongson-i2s.o
 
-snd-soc-loongson-i2s-plat-y := loongson_i2s_plat.o loongson_i2s.o
-obj-$(CONFIG_SND_SOC_LOONGSON_I2S_PLATFORM) += snd-soc-loongson-i2s-plat.o
+snd-soc-loongson-i2s-plat-y := loongson_i2s_plat.o
+obj-$(CONFIG_SND_SOC_LOONGSON_I2S_PLATFORM) += snd-soc-loongson-i2s-plat.o snd-soc-loongson-i2s.o
+
+snd-soc-loongson-i2s-y := loongson_i2s.o
 
 #Machine Support
 snd-soc-loongson-card-y := loongson_card.o

sound/soc/loongson/loongson_i2s.c

@@ -246,6 +246,7 @@ struct snd_soc_dai_driver loongson_i2s_dai = {
 	.ops = &loongson_i2s_dai_ops,
 	.symmetric_rate = 1,
 };
+EXPORT_SYMBOL_GPL(loongson_i2s_dai);
 
 static int i2s_suspend(struct device *dev)
 {
@@ -268,3 +269,7 @@ static int i2s_resume(struct device *dev)
 const struct dev_pm_ops loongson_i2s_pm = {
 	SYSTEM_SLEEP_PM_OPS(i2s_suspend, i2s_resume)
 };
+EXPORT_SYMBOL_GPL(loongson_i2s_pm);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Common functions for loongson I2S controller driver");