hw/arm/aspeed: Fix build issue with clang 3.4

hw/arm/aspeed: Fix build issue with clang 3.4

When using clang 3.4.2, compilation of QEMU fails like this:

  CC      aarch64-softmmu/hw/arm/aspeed.o
hw/arm/aspeed.c:36:3: error: redefinition of typedef 'AspeedBoardState' is a C11
      feature [-Werror,-Wtypedef-redefinition]
} AspeedBoardState;
  ^
include/hw/arm/aspeed.h:14:33: note: previous definition is here
typedef struct AspeedBoardState AspeedBoardState;
                                ^
1 error generated.
make[1]: *** [hw/arm/aspeed.o] Error 1
make: *** [subdir-aarch64-softmmu] Error 2

Remove the duplicated typedef to fix this issue.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-id: 1543397736-8198-1-git-send-email-thuth@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>