EmbeddedPkg/TimeBaseLib: Update comment blocks for API functions
This updates Doxygen comment blocks for API library functions.
Cc: Leif Lindholm <leif@nuviainc.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Signed-off-by: Nhi Pham <nhi@os.amperecomputing.com>
Reviewed-by: Leif Lindholm <leif@nuviainc.com>