update code base to Marlin 2.0.9.2

Marlin/src/sd/SdFatUtil.cpp

@@ -16,11 +16,13 @@
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
 
 /**
+ * sd/SdFatUtil.cpp
+ *
  * Arduino SdFat Library
  * Copyright (c) 2008 by William Greiman
  *
@@ -46,7 +48,7 @@
     return &top - reinterpret_cast<char*>(sbrk(0));
   }
 
-#else
+#elif defined(__AVR__)
 
   extern char* __brkval;
   extern char __bss_end;