remove redundant SQ definitions

src/core2/code_7AF80.c

@@ -4,10 +4,9 @@
 
 #include <core1/viewport.h>
 #include <core2/file.h>
+#include <math.h>
 #include "prop.h"
 
-#define SQ(x) ((x) * (x))
-
 extern f32 ml_distanceSquared_vec3f(f32[3], f32[3]);
 extern f32 func_802586B0(f32[3], f32[3]);
 extern void mapModel_getCubeBounds(s32 min[3], s32 max[3]);