replace fontrenderer.h include with forward declaration

in order to flatten the build dependency tree further, include
fontrenderer.h directly where needed, in header files a forward
declaration is enough

src/gui/components/cc_frm_footer.cpp

@@ -29,6 +29,7 @@
 #include <gui/color_custom.h>
 #include "cc_frm_footer.h"
 #include <system/debug.h>
+#include <driver/fontrenderer.h>
 
 using namespace std;