KVM: x86: Open code necessary bits of kvm_lapic_set_base() at vCPU RESET

KVM: x86: Open code necessary bits of kvm_lapic_set_base() at vCPU RESET

Stuff vcpu->arch.apic_base and apic->base_address directly during APIC
reset, as opposed to bouncing through kvm_set_apic_base() while fudging
the ENABLE bit during creation to avoid the other, unwanted side effects.

This is a step towards consolidating the APIC RESET logic across x86,
VMX, and SVM.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210713163324.627647-18-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>