Fix compiling issues (hopefully)

source/gfx/gfx.c

@@ -20,6 +20,9 @@
 #include <string.h>
 #include "gfx.h"
 
+gfx_ctxt_t gfx_ctxt;
+gfx_con_t gfx_con;
+
 static const u8 _gfx_font[] = {
 	0x00, 0x0C, 0x12, 0x7E, 0x42, 0x42, 0x7E, 0x00, // Char 030 (folder)
 	0x00, 0x0E, 0x12, 0x22, 0x22, 0x22, 0x3E, 0x00, // Char 031 (file)

source/gfx/gfx.h

@@ -61,7 +61,7 @@ void gfx_boxGrey(int x0, int y0, int x1, int y1, u8 shade);
 */
 
 // Global gfx console and context.
-gfx_ctxt_t gfx_ctxt;
-gfx_con_t gfx_con;
+extern gfx_ctxt_t gfx_ctxt;
+extern gfx_con_t gfx_con;
 
 #endif