spi: AD ASoC: declare missing of table

Add missing <of_device_id> table for SPI driver relying on SPI
device match since compatible is in a DT binding or in a DTS.

Before this patch:
modinfo sound/soc/codecs/snd-soc-adau1977-spi.ko | grep alias
alias:          spi:adau1979
alias:          spi:adau1978
alias:          spi:adau1977

After this patch:
modinfo sound/soc/codecs/snd-soc-adau1977-spi.ko | grep alias
alias:          of:N*T*Cadi,adau1979C*
alias:          of:N*T*Cadi,adau1979
alias:          of:N*T*Cadi,adau1978C*
alias:          of:N*T*Cadi,adau1978
alias:          of:N*T*Cadi,adau1977C*
alias:          of:N*T*Cadi,adau1977
alias:          spi:adau1979
alias:          spi:adau1978
alias:          spi:adau1977
Reported-by: Javier Martinez Canillas <javier@dowhile0.org>
Signed-off-by: Daniel Gomez <dagmcr@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/adau1977-spi.c

@@ -10,6 +10,8 @@
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/regmap.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/spi/spi.h>
 #include <sound/soc.h>
 
@@ -54,9 +56,18 @@ static const struct spi_device_id adau1977_spi_ids[] = {
 };
 MODULE_DEVICE_TABLE(spi, adau1977_spi_ids);
 
+static const struct of_device_id adau1977_spi_of_match[] = {
+        { .compatible = "adi,adau1977" },
+        { .compatible = "adi,adau1978" },
+        { .compatible = "adi,adau1979" },
+        { },
+};
+MODULE_DEVICE_TABLE(of, adau1977_spi_of_match);
+
 static struct spi_driver adau1977_spi_driver = {
 	.driver = {
 		.name = "adau1977",
+		.of_match_table = of_match_ptr(adau1977_spi_of_match),
 	},
 	.probe = adau1977_spi_probe,
 	.id_table = adau1977_spi_ids,