drm/i915: remove an extra #define for DP_RECEIVER_CAP_SIZE

Identical #define is now available in include/drm/drm_dp_helper.h, nuke the
dupe.
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_drv.h

@@ -343,7 +343,6 @@ struct intel_hdmi {
 			       struct drm_display_mode *adjusted_mode);
 };
 
-#define DP_RECEIVER_CAP_SIZE		0xf
 #define DP_MAX_DOWNSTREAM_PORTS		0x10
 #define DP_LINK_CONFIGURATION_SIZE	9