Replace solitaire use of u8g_font_5x8 font and replace with u8g_font_6x10_marlin

and win another 1694 bytes.

Marlin/dogm_lcd_implementation.h

@@ -110,13 +110,13 @@ static void lcd_implementation_init()
   // Show splashscreen
   int offx = (u8g.getWidth() - START_BMPWIDTH) / 2;
   int offy = (u8g.getHeight() - 18 - START_BMPHEIGHT) / 2;
-  int txtX = (u8g.getWidth() - (sizeof(STRING_SPLASH) - 1)*5) / 2; // 5 is fontwidth in pixel
+  int txtX = (u8g.getWidth() - (sizeof(STRING_SPLASH) - 1)*6) / 2; // 6 is fontwidth in pixel
   int txtY = u8g.getHeight() - 10;
 	u8g.firstPage();
 	do {
 	  u8g.drawBitmapP(offx, offy, START_BMPBYTEWIDTH, START_BMPHEIGHT, start_bmp);
 			
-    u8g.setFont(u8g_font_5x8);
+    u8g.setFont(u8g_font_6x10_marlin);
 		u8g.drawStr(txtX, txtY, STRING_SPLASH);
 	} while(u8g.nextPage());
 }