🏗️ Extend AXIS_CHAR to include E

Co-Authored-By: DerAndere <26200979+DerAndere1@users.noreply.github.com>

Marlin/src/lcd/tft/tft_string.cpp

@@ -116,7 +116,7 @@ void TFT_String::add(const char *tpl, const int8_t index, const char *cstr/*=nul
     else if (ch == '$' && cstr)
       add(cstr);
     else if (ch == '@')
-      add_character(axis_codes[index]);
+      add_character(AXIS_CHAR(index));
     else
       add_character(ch);
   }