SourceLevelDebugPkg/DxeDebugAgent: Initialize Local APIC Timer

SourceLevelDebugPkg/DxeDebugAgent: Initialize Local APIC Timer

Now Debug Agent library uses Local APIC Timer to implement time-out mechanism.
For AP, its local APIC timer may not work. This fix is to initialize Local
APIC timer if it doesn't work as expected when debugging AP function.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@17604 6f19259b-4bc3-4df7-8a09-765794883524