Use macro QEMU_PACKED for new packed structures

Since commit 541dc0d47f,
some new packed structures were added without using QEMU_PACKED.

QEMU_PACKED is needed for compilations with MinGW.
For other platforms nothing changes.

The code was fixed using this command:

    git grep -la '__attribute__ ((packed))'|xargs perl -pi -e 's/__attribute__ \(\(packed\)\)/QEMU_PACKED/'

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

hw/ppce500_spin.c

@@ -40,7 +40,7 @@ typedef struct spin_info {
     uint32_t resv;
     uint32_t pir;
     uint64_t reserved;
-} __attribute__ ((packed)) SpinInfo;
+} QEMU_PACKED SpinInfo;
 
 typedef struct spin_state {
     SysBusDevice busdev;