ASoC: Intel: avs: PCM power management

Merge series from Cezary Rojewski <cezary.rojewski@intel.com>:

Goal of the series is implementation of suspend/resume operations for a
PCM stream along with all the collaterals connected to the subject.

Start with splitting avs_dai_fe_hw_free() as ideally we would like to
reuse as much of existing code as possible but snd_pcm_lib_free_pages()
is not desired part of the function when speaking of suspend operation.

The actual implementation of suspend/resume() for component drivers
follows. For most scenarios, the PM flow is similar to standard
streaming one, except for the part where the position register are being
saved and the lack of PCM pages freeing. To reduce code duplication, all
avs_dai_suspend_XXX() and avs_dai_resume_XXX() functions reuse their
non-PM equivalents.
Order of operations is affected by the fact that path binding/unbinding
happens only in FE part of the stream.

Above essentially unlocks SX+streaming scenarios i.e.: power transitions
with an ongoing stream.

As some streams are allowed to run in low power state, support is
provided for S0iX state. The handlers check ACPI capabilities and the
number of active low-power paths before deciding between SX and S0iX
flows.

The last portion of the patchset is addition of power/clock gating
overrides. There is no single set of registers that ensures AudioDSP
firmware loads 100% of time on every single configuration. By having
them exposed, user can have the loading procedure behavior adjusted for
their configuration without having to recompile the kernel.