KVM: x86/emulator: emulate movbe with operand-size prefix

The MOVBE instruction can come with an operand-size prefix (66h). In
this, case the x86 emulation code returns EMULATION_FAILED.

It turns out that em_movbe can already handle this case and all that
is missing is an entry in respective opcode tables to populate
gprefix->pfx_66.

Signed-off-by: Thomas Prescher <thomas.prescher@cyberus-technology.de>
Signed-off-by: Julian Stecklina <julian.stecklina@cyberus-technology.de>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20231212095938.26731-1-julian.stecklina@cyberus-technology.de


Signed-off-by: Sean Christopherson <seanjc@google.com>