Fix cpuid leaf 0x0d which incorrectly parsed eax and ebx.

However, before this patch the CPUID worked fine -- the .offset
field contained the size _and_ was stored in the register that
is supposed to hold the size (eax), and likewise the .size field
contained the offset _and_ was stored in the register trhat is
supposed to hold the offset (ebx).
Signed-off-by: NLiu Jinsong <jinsong.liu@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>