Sync kexec test case to upstream.


This case need call rh_kernel_update script when only one kernel in guest.

We will sync rh_kernel_update late. May need some update again at that time.

Sync this case to upstream first.
Thanks

Design this case according to manual case
[x2APIC] switch kernel with kexec

This case check that x2apic is still enabled after kexec.

changelog for v2:
Check x2apic flag in guest before/after kexec command.

Signed-off-by: Feng Yang <fyang@redhat.com>