MIPS: CI20: Add second percpu timer for SMP.

1.Add a new TCU channel as the percpu timer of core1, this is to
  prepare for the subsequent SMP support. The newly added channel
  will not adversely affect the current single-core state.
2.Adjust the position of TCU node to make it consistent with the
  order in jz4780.dtsi file.

Tested-by: Nikolaus Schaller <hns@goldelico.com> # on CI20
Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
Acked-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>