ASoC: mediatek: use reserved memory or enable

Merge series from Chen-Yu Tsai <wenst@chromium.org>:

Angelo requested that these platforms use reserved memory regions if
possible, and fall back to pre-allocated buffers only if that fails,
to align with other MediaTek SoCs / platforms that already use reserved
memory. The series covers MediaTek's MT8173, MT8183, MT8186, and MT8192
SoCs.

There are three parts to the series:

- Part one (patches 1 through 5) update the DT bindings to allow having
  a memory region. The text binding for the MT8173 was converted to YAML
  and also aligned with current usage by addition of a power domain.

  Note that the MT8183 text binding was _not_ converted. It is
  drastically different from what was landed in the device trees. Some
  time is needed to work out the differences. I might try to recombine
  the audio clocks (which are actually part of the same hardware block)
  as well.

- Part two (patches 6 through 9) update the audio frontend drivers for
  the various platforms covered in this series.

  - Patch 6 is the evolution of version 1, now defaulting to reserved
    memory if possible.

  - Patch 7 adds support for >32 bit DMA addresses to the MT8183 driver.
    This was missing, and prevents the memory regions, which are
    allocated from the top end of main memory by default, from working.

  - Patch 8 and 9 are just some minor cleanups to reduce the number of
    "&pdev->dev" style dereferences. They are placed after the other
    changes to make it easier for the fixes to be backported.

- Part three (patches 10 through 13) add a reserved memory region for
  the audio frontend on the various platforms. (This part is queued up
  and therefore not included in v3.)

  For the MT8173, the change covers the whole platform. In practice
  there are only ChromeOS devices.

  For the other platforms, only the ChromeOS devices are covered. These
  are what I have available for testing.

Please have a look. I assume the DT binding and driver changes will go
through the ASoC tree, while the device tree changes will go through the
MediaTek tree.