hw/display/sm501: Remove unused include

The "cpu.h" include makes devices target-specific. Since it
is not used, remove it, so the device become generic (we can
now compile it once for all targets).

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20190812113739.16587-2-philmd@redhat.com>
[lv: fix conflict with 650d103d3ea9
     ("Include hw/hw.h exactly where needed")]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

hw/display/sm501.c

@@ -28,7 +28,6 @@
 #include "qapi/error.h"
 #include "qemu/log.h"
 #include "qemu/module.h"
-#include "cpu.h"
 #include "hw/char/serial.h"
 #include "ui/console.h"
 #include "hw/sysbus.h"