drm/i915: remove unused/stale macros and comments from intel_drv.h

Reduce clutter from intel_drv.h.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/963ba7fa0111135c3e796bfc9f86d6e33724758e.1556809195.git.jani.nikula@intel.com

drivers/gpu/drm/i915/intel_drv.h

@@ -158,15 +158,6 @@ struct drm_printer;
  * Display related stuff
  */
 
-/* store information about an Ixxx DVO */
-/* The i830->i865 use multiple DVOs with multiple i2cs */
-/* the i915, i945 have a single sDVO i2c bus - which is different */
-#define MAX_OUTPUTS 6
-/* maximum connectors per crtcs in the mode set */
-
-#define INTEL_I2C_BUS_DVO 1
-#define INTEL_I2C_BUS_SDVO 2
-
 /* these are outputs from the chip - integrated only
    external chips are via DVO or SDVO output */
 enum intel_output_type {