Allow use of either SD Card slot when LCD Panel is configured.

Preference is for Controller SD slot before LCD Panel slot when both are occupied.

Marlin/cardreader.cpp

@@ -150,9 +150,17 @@ void CardReader::initsd()
   if(root.isOpen())
     root.close();
 #ifdef SDSLOW
-  if (!card.init(SPI_HALF_SPEED,SDSS))
+  if (!card.init(SPI_HALF_SPEED,SDSS)
+  #if defined(LCD_SDSS) && (LCD_SDSS != SDSS)
+    && !card.init(SPI_HALF_SPEED,LCD_SDSS)
+  #endif
+    )
 #else
-  if (!card.init(SPI_FULL_SPEED,SDSS))
+  if (!card.init(SPI_FULL_SPEED,SDSS)
+  #if defined(LCD_SDSS) && (LCD_SDSS != SDSS)
+    && !card.init(SPI_FULL_SPEED,LCD_SDSS)
+  #endif
+    )
 #endif
   {
     //if (!card.init(SPI_HALF_SPEED,SDSS))