Remove unused "MAX_PATH" header

The header's name was also quite misleading.
Also remove an unused define in `asm/symbol.h`.

include/asm/fstack.h

@@ -19,7 +19,6 @@
 
 #include "asm/lexer.h"
 
-#include "types.h"
 
 struct FileStackNode {
 	struct FileStackNode *parent; /* Pointer to parent node, for error reporting */

include/asm/symbol.h

@@ -17,10 +17,8 @@
 #include "asm/section.h"
 
 #include "platform.h" // MIN_NB_ELMS
-#include "types.h"
 
-#define HASHSIZE	(1 << 16)
-#define MAXSYMLEN	256
+#define MAXSYMLEN	255
 
 enum SymbolType {
 	SYM_LABEL,

include/types.h

@@ -1,16 +0,0 @@
-/*
- * This file is part of RGBDS.
- *
- * Copyright (c) 1997-2018, Carsten Sorensen and RGBDS contributors.
- *
- * SPDX-License-Identifier: MIT
- */
-
-#ifndef RGBDS_TYPES_H
-#define RGBDS_TYPES_H
-
-#ifndef _MAX_PATH
-#define _MAX_PATH 512
-#endif
-
-#endif /* RGBDS_TYPES_H */