drm/i915: add new intel audio file to group DP/HDMI audio

In preparation for some additional cleanup. No functional changes.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --cc drivers/gpu/drm/i915/Makefile
Simple merge

diff --cc drivers/gpu/drm/i915/intel_audio.c
Simple merge

diff --cc drivers/gpu/drm/i915/intel_display.c
Simple merge

diff --cc drivers/gpu/drm/i915/intel_drv.h
Simple merge