misc/aspeed_scu: Fix build error caused by missing header

Tracing configurations error out currently as follows:

/home/travis/build/pranith/qemu/hw/misc/aspeed_scu.c: In function ‘aspeed_scu_read’:
/home/travis/build/pranith/qemu/hw/misc/aspeed_scu.c:130:9: error: implicit declaration of function ‘qemu_log_mask’ [-Werror=implicit-function-declaration]
/home/travis/build/pranith/qemu/hw/misc/aspeed_scu.c:130:9: error: nested extern declaration of ‘qemu_log_mask’ [-Werror=nested-externs]
/home/travis/build/pranith/qemu/hw/misc/aspeed_scu.c:130:23: error: ‘LOG_GUEST_ERROR’ undeclared (first use in this function)
/home/travis/build/pranith/qemu/hw/misc/aspeed_scu.c:130:23: note: each undeclared identifier is reported only once for each function it appears in
/home/travis/build/pranith/qemu/hw/misc/aspeed_scu.c: In function ‘aspeed_scu_write’:
/home/travis/build/pranith/qemu/hw/misc/aspeed_scu.c:154:23: error: ‘LOG_GUEST_ERROR’ undeclared (first use in this function)

This is caused by a missing header file. Fix it.
Signed-off-by: NPranith Kumar <bobby.prani@gmail.com>
Reviewed-by: NAndrew Jeffery <andrew@aj.id.au>
Message-id: 20160627215304.821-1-bobby.prani@gmail.com
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

hw/misc/aspeed_scu.c

@@ -15,6 +15,7 @@
 #include "qapi/error.h"
 #include "qapi/visitor.h"
 #include "qemu/bitops.h"
+#include "qemu/log.h"
 #include "trace.h"
 
 #define TO_REG(offset) ((offset) >> 2)