Add BaseTscTimerLib, and then merge the three TscTimerLib to one directory.

Signed-off-by: lzeng14
Reviewed-by: lgao4

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12604 6f19259b-4bc3-4df7-8a09-765794883524
10 files changed