i.mx7d: Remove unused header files

Signed-off-by: NJean-Christophe Dubois <jcd@tribudubois.net>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

hw/arm/mcimx7d-sabre.c

@@ -18,10 +18,8 @@
 #include "hw/arm/fsl-imx7.h"
 #include "hw/boards.h"
 #include "sysemu/sysemu.h"
-#include "sysemu/device_tree.h"
 #include "qemu/error-report.h"
 #include "sysemu/qtest.h"
-#include "net/net.h"
 
 typedef struct {
     FslIMX7State soc;