hw/arm/smmuv3: Fix IIDR offset

The SMMU IIDR register is at 0x018 offset.

Fixes: 10a83cb ("hw/arm/smmuv3: Skeleton")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20200728150815.11446-9-eric.auger@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/arm/smmuv3-internal.h

@@ -63,7 +63,7 @@ REG32(IDR5,                0x14)
 
 #define SMMU_IDR5_OAS 4
 
-REG32(IIDR,                0x1c)
+REG32(IIDR,                0x18)
 REG32(CR0,                 0x20)
     FIELD(CR0, SMMU_ENABLE,   0, 1)
     FIELD(CR0, EVENTQEN,      2, 1)