sound: Add an ACPI driver for Maxim MAX98357ac

This chip is used on coral and we need to generate ACPI tables for sound
to make it work. Add a driver that does just this (i.e. at present does
not actually support playing sound).

Signed-off-by: Simon Glass <sjg@chromium.org>
[bmeng: Use the correct acpi_irq_polarity enum number]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/sound/Kconfig b/drivers/sound/Kconfig
index 7f214b9..0948d8c 100644
--- a/drivers/sound/Kconfig
+++ b/drivers/sound/Kconfig
@@ -113,6 +113,15 @@
 	  audio data and I2C for codec control. At present it only works
 	  with the Samsung I2S driver.
 
+config SOUND_MAX98357A
+	bool "Support Maxim max98357a audio codec"
+	depends on PCI
+	help
+	  Enable the max98357a audio codec. This is connected on PCI for
+	  audio data codec control. This is currently only capable of providing
+	  ACPI information. A full driver (with sound in U-Boot) is currently
+	  not available.
+
 config SOUND_RT5677
 	bool "Support Realtek RT5677 audio codec"
 	depends on SOUND