ASoC: SOF: Intel: refactor i915_get/put functions

The current interface to control i915 display power is misleading.
The hda_codec_i915_get() and hda_codec_i915_put() names suggest
a refcounting based interface. This is confusing as no refcounting
is done and the underlying HDAC library interface does not support
refcounts eithers.

Clarify the code by replacing the functions with a single
hda_codec_i915_display_power() that is aligned with
snd_hdac_display_power().

Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20200120160117.29130-2-kai.vehmanen@linux.intel.com


Acked-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>