hw/display/edid: Add missing 'qdev-properties.h' header

When trying to consume the DEFINE_EDID_PROPERTIES() macro
by including "hw/display/edid.h", we get this build failure:

  include/hw/display/edid.h:24:5: error: implicit declaration of
  function ‘DEFINE_PROP_UINT32’ [-Werror=implicit-function-declaration]
     24 |     DEFINE_PROP_UINT32("xres", _state, _edid_info.prefx, 0),    \
        |     ^~~~~~~~~~~~~~~~~~

Headers should be self-contained, and one shouldn't have to
dig to find the missing headers.
In this case "hw/qdev-properties.h" is missing. Add it.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20200526062252.19852-2-f4bug@amsat.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

include/hw/display/edid.h

@@ -2,6 +2,7 @@
 #define EDID_H
 
 #include "qom/object.h"
+#include "hw/qdev-properties.h"
 
 typedef struct qemu_edid_info {
     const char *vendor; /* http://www.uefi.org/pnp_id_list */