ACPI / LPSS: add LPSS device for Wildcat Point PCH

INT3438 is the ADSP device on Wildcat Point platform
with 2 DW DMA engines built In. The DMA engines are
used for DSP FW loading and audio data transferring.
These DMA engine probing need the clock, without it,
probing may failed and can't go forward.

Add LPSS device "INT3438" for Wildcat Point PCH, to
provide clock for its ADSP DMA engine probing.

Signed-off-by: Jie Yang <yang.jie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Merge branch 'acpi-lpss' into bleeding-edge

* acpi-lpss:
  ACPI / LPSS: add LPSS device for Wildcat Point PCH