sa1: combine collision.c files

Author: freshollie

sa1/ldscript.txt

@@ -28,7 +28,6 @@ SECTIONS {
         /* Game */
         src/game/shared/stage/rings_manager.o(.text);
         src/game/shared/stage/entities_manager.o(.text);
-        src/game/shared/stage/collision_0.o(.text);
         src/game/shared/stage/collision.o(.text);
         sa2/src/game/shared/stage/palette_loader.o(.text);