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/epgview.cpp

@@ -52,6 +52,7 @@
 #include <gui/pictureviewer.h>
 #include <gui/tmdb.h>
 #include <driver/record.h>
+#include <driver/fontrenderer.h>
 
 #include <zapit/bouquets.h>
 #include <zapit/getservices.h>