[ALSA] add CMI8788 driver

Add the snd-oxygen driver for the C-Media CMI8788 (Oxygen) chip, used on
the Asound A-8788, AuzenTech X-Meridian, Bgears b-Enspirer,
Club3D Theatron DTS, HT-Omega Claro, Razer Barracuda AC-1,
Sondigo Inferno, and TempoTec HIFIER sound cards.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
diff --git a/sound/pci/oxygen/Makefile b/sound/pci/oxygen/Makefile
new file mode 100644
index 0000000..99455dd
--- /dev/null
+++ b/sound/pci/oxygen/Makefile
@@ -0,0 +1,5 @@
+snd-oxygen-lib-objs := oxygen_io.o oxygen_lib.o oxygen_mixer.o oxygen_pcm.o
+snd-oxygen-objs := oxygen.o
+
+obj-$(CONFIG_SND_OXYGEN_LIB) += snd-oxygen-lib.o
+obj-$(CONFIG_SND_OXYGEN) += snd-oxygen.o