Fix header references for noxary 268 keyboard (#3359)

Brown paper bag.

keyboards/noxary/268/268.c

@@ -1 +1 @@
-#include "noxary268.h"
+#include "268.h"

keyboards/noxary/268/keymaps/default/keymap.c

@@ -1,4 +1,4 @@
-#include "noxary268.h"
+#include "268.h"
 
 // Helpful defines
 #define _______ KC_TRNS

keyboards/noxary/268/keymaps/sixtyeight/keymap.c

@@ -1,4 +1,4 @@
-#include "noxary268.h"
+#include "268.h"
 
 // Helpful defines
 #define _______ KC_TRNS