mesa: Clean up header file inclusion in texformat.h.

src/mesa/main/texformat.h

@@ -27,9 +27,9 @@
 #define TEXFORMAT_H
 
 
-#include "mtypes.h"
 #include "formats.h"
 
+struct gl_context;
 
 extern gl_format
 _mesa_choose_tex_format( struct gl_context *ctx, GLint internalFormat,