drm/i915/audio: rename intel_init_audio_hooks to intel_audio_hooks_init

Follow the filename based prefix naming.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211104161858.21786-6-jani.nikula@intel.com