global.h: Use forward-declarations to reduce number of dependencies

src/driver/record.cpp

@@ -52,6 +52,7 @@
 
 
 #include <driver/record.h>
+#include <driver/radiotext.h>
 #include <driver/streamts.h>
 #include <zapit/capmt.h>
 #include <zapit/channel.h>

src/driver/volume.cpp

@@ -34,6 +34,7 @@
 #include <audio_cs.h>
 #include <system/settings.h>
 #include <daemonc/remotecontrol.h>
+#include <driver/display.h>
 #include <driver/volume.h>
 #include <gui/audiomute.h>
 #include <gui/mediaplayer.h>