Remove unfinished OpenGL display list code

It seems unlikely anyone is going to do anything with this aside from stub
it out in OpenGLES ports.

code/renderergl2/tr_local.h

@@ -848,7 +848,6 @@ typedef enum {
 	SF_IQM,
 	SF_FLARE,
 	SF_ENTITY,				// beams, rails, lightning, etc that can be determined by entity
-	SF_DISPLAY_LIST,
 	SF_VAO_MESH,
 	SF_VAO_MDVMESH,
 
@@ -877,11 +876,6 @@ typedef struct srfPoly_s {
 	polyVert_t		*verts;
 } srfPoly_t;
 
-typedef struct srfDisplayList_s {
-	surfaceType_t	surfaceType;
-	int				listNum;
-} srfDisplayList_t;
-
 
 typedef struct srfFlare_s {
 	surfaceType_t	surfaceType;