whp: add Hyper-V enlightenment support and invariant TSC

[lstocchi]

Configure the WHP partition to expose Hyper-V enlightenments to the guest, enabling it to use synthetic MSRs for timekeeping and hypercalls instead of expensive VM exits on native hardware interfaces.

• Advertise Hyper-V CPUID leaves 0x40000000–0x40000006 (signature, interface ID, version, feature identification, recommendations, implementation limits, and hardware features).
• Enable synthetic processor features: HypervisorPresent, Hv1, reference TSC, reference counter, frequency registers, hypercalls, and VP index/runtime access.
• Set the MSR exit bitmap so unhandled MSR accesses trigger a VM exit rather than injecting #GP into the guest.
• Retrieve and re-apply processor features banks with the invariant TSC bit set, and expose it via CPUID 0x80000007.
• Register CPUID leaf 1 in the exit list so the hypervisor-present bit (ECX.31) can be injected, which is required for the guest to query the 0x40000000+ range.