KVM: nVMX: set IDTR and GDTR limits when loading L1 host state

Intel SDM 27.5.2 Loading Host Segment and Descriptor-Table Registers:

"The GDTR and IDTR limits are each set to FFFFH."

Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>