x86/apic: Read and write LVT* APIC registers from HV for SAVIC guests

x86/apic: Read and write LVT* APIC registers from HV for SAVIC guests

The Hypervisor needs information about the current state of the LVT registers
for device emulation and NMIs. So, forward reads and write of these registers
to the hypervisor for Secure AVIC enabled guests.

Signed-off-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Link: https://lore.kernel.org/20250828111356.208972-1-Neeraj.Upadhyay@amd.com