drm/i915: small hdmi coding style cleanups

- Changed the coding style of auxiliary infoframe functions to make
  them smaller
- Fixed the column alignment of some function definitions
- Remove definition of "struct drm_crtc" in some places as they're
  used only to retrieve "struct intel_crtc"

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>