nb/intel/haswell: Add HDAU ACPI device

The HDAU stub device enables HDMI audio under MacOS.

Change-Id: Ifa2155512dd909a4e4a753f6475541e9410dfe91
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58272
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/northbridge/intel/haswell/acpi/hostbridge.asl

@@ -203,3 +203,9 @@ Device (PDRC)
 
 /* Integrated graphics 0:2.0 */
 #include <drivers/intel/gma/acpi/gfx.asl>
+
+/* Intel Mini-HD 0:03.0 */
+Device (HDAU)
+{
+	Name (_ADR, 0x00030000)
+}