Add the debugging message to monitor the CPU auto hotplug process.

Reviewed-on: http://mcrd1-5.corpnet.asus/code-review/master/46928
Reviewed-by: Singhome Lee <singhome_lee@asus.com>
Tested-by: Singhome Lee <singhome_lee@asus.com>
Change-Id: I31049d0ae097a8e45b5ecb22ab0961a9c85935b5
Reviewed-on: http://mcrd1-5.corpnet.asus/code-review/master/48085
Tested-by: Jive Hwang <jive_hwang@asus.com>
Reviewed-by: Jive Hwang <jive_hwang@asus.com>