purism/librem13v2: Add audio support

Initialize the audio codec without depending on DSP binary blobs.
The hda_verb.c was copied from the intel/kblrvp rvp7 variant, and the
hda_verb.h file was copied from the purism/librem13.

The IoBufferOwnership FSP option in devicetree has to be 0 for the azalia
driver to work.

Change-Id: Ifa36ac0839daedfa59c497057da0ace04d401f2a
Signed-off-by: Youness Alaoui <youness.alaoui@puri.sm>
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/19943
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>
diff --git a/src/mainboard/purism/librem13v2/devicetree.cb b/src/mainboard/purism/librem13v2/devicetree.cb
index f345c09..e113b3f 100644
--- a/src/mainboard/purism/librem13v2/devicetree.cb
+++ b/src/mainboard/purism/librem13v2/devicetree.cb
@@ -34,8 +34,8 @@
 	register "SataPortsEnable[0]" = "1"
 	register "SataPortsEnable[2]" = "1"
 	register "EnableAzalia" = "1"
-	register "DspEnable" = "1"
-	register "IoBufferOwnership" = "3"
+	register "DspEnable" = "0"
+	register "IoBufferOwnership" = "0"
 	register "EnableTraceHub" = "0"
 	register "XdciEnable" = "0"
 	register "SsicPortEnable" = "0"