Suppress U8glib build warnings

Marlin/src/HAL/HAL_DUE/u8g_com_HAL_DUE_shared_hw_spi.cpp

@@ -62,7 +62,10 @@
 
 #if ENABLED(DOGLCD)
 
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wuninitialized"
 #include <U8glib.h>
+#pragma GCC diagnostic pop
 
 #include "../../Marlin.h"
 

Marlin/src/HAL/HAL_DUE/u8g_com_HAL_DUE_st7920_sw_spi.cpp

@@ -59,7 +59,10 @@
 
 #if ENABLED(DOGLCD)
 
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wuninitialized"
 #include <U8glib.h>
+#pragma GCC diagnostic pop
 #include <Arduino.h>
 #include "../Delay.h"