KVM: x86/mmu: Set shadow_accessed_mask for EPT even if A/D bits disabled

KVM: x86/mmu: Set shadow_accessed_mask for EPT even if A/D bits disabled

Now that KVM doesn't use shadow_accessed_mask to detect if hardware A/D
bits are enabled, set shadow_accessed_mask for EPT even when A/D bits
are disabled in hardware.  This will allow using shadow_accessed_mask for
software purposes, e.g. to preserve accessed status in a non-present SPTE
acros NUMA balancing, if something like that is ever desirable.

Link: https://lore.kernel.org/r/20241011021051.1557902-11-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>