x86: sound: Add support for broadwell I2S

I2S is used to send digital audio data to an audio codec. Add support for
this on broadwell.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/sound/Makefile b/drivers/sound/Makefile
index 2a6fd74..07b5901 100644
--- a/drivers/sound/Makefile
+++ b/drivers/sound/Makefile
@@ -17,4 +17,5 @@
 obj-$(CONFIG_SOUND_MAX98095)	+= max98095.o maxim_codec.o
 obj-$(CONFIG_SOUND_INTEL_HDA)	+= hda_codec.o
 obj-$(CONFIG_SOUND_I8254)	+= i8254_beep.o
+obj-$(CONFIG_INTEL_BROADWELL)	+= broadwell_i2s.o
 obj-$(CONFIG_SOUND_IVYBRIDGE)	+= ivybridge_sound.o