Don't include cpu.h in timer.h

Change the name of the define used to indicate SVGA multi-monitor-capable cards

src/device/cartridge.c

@@ -22,6 +22,7 @@
 #include <wchar.h>
 #define HAVE_STDARG_H
 #include <86box/86box.h>
+#include "cpu.h"
 #include <86box/timer.h>
 #include <86box/plat.h>
 #include <86box/ui.h>

src/device/keyboard_xt.c

@@ -29,6 +29,7 @@
 #include <wchar.h>
 #include <86box/86box.h>
 #include <86box/device.h>
+#include "cpu.h"
 #include <86box/timer.h>
 #include <86box/fdd.h>
 #include <86box/machine.h>

src/device/serial.c

@@ -27,6 +27,7 @@
 #define HAVE_STDARG_H
 #include <86box/86box.h>
 #include <86box/device.h>
+#include "cpu.h"
 #include <86box/timer.h>
 #include <86box/machine.h>
 #include <86box/io.h>