x86/emul: Move CPUID Faulting fault generation into the emulator

x86/emul: Move CPUID Faulting fault generation into the emulator

In hindsight, this is a better position for it, as it avoids opencoding
hvmemul_inject_hw_exception() in hvmemul_cpuid(), and reduces the requirements
on other ops->cpuid() hooks wanting to implement cpuid faulting in the future.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>