kvm-unit-tests: VMX: Add test cases for PAT and EFER

Add test cases for ENT_LOAD_PAT, ENT_LOAD_EFER, EXI_LOAD_PAT,
EXI_SAVE_PAT, EXI_LOAD_EFER, EXI_SAVE_PAT flags in enter/exit
control fields.

Signed-off-by: Arthur Chunqi Li <yzt356@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>