intel_th: Add ACPI glue layer

The Trace Hub devices now can be enumerated as ACPI devices, which
translates into "Host Debugger mode". There are two IDs: one for
PCH Trace Hub, and one for the uncore Trace Hub. These are expected
to stay the same across all platforms.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>