KVM: vmx: print more APICv fields in dump_vmcs

The SVI, RVI, virtual-APIC page address and APIC-access page address fields
were left out of dump_vmcs.  Add them.

KERN_CONT technically isn't SMP safe, but it's okay to use it here since
the whole of dump_vmcs() is a single huge multi-line piece of output
that isn't SMP-safe.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>