Introduce SMP support for CI20 (based on JZ4780) v8.

Subject: Introduce SMP support for CI20 (based on JZ4780) v8.
From: 周琰杰 (Zhou Yanjie) <zhouyanjie@xxxxxxxxxxxxxx>
Date: Tue, 19 May 2020 22:35:16 +0800
Cc: linux-kernel@xxxxxxxxxxxxxxx, devicetree@xxxxxxxxxxxxxxx, tsbogend@xxxxxxxxxxxxxxxx, paulburton@xxxxxxxxxx, jiaxun.yang@xxxxxxxxxxx, chenhc@xxxxxxxxxx, tglx@xxxxxxxxxxxxx, robh+dt@xxxxxxxxxx, daniel.lezcano@xxxxxxxxxx, keescook@xxxxxxxxxxxx, paul@xxxxxxxxxxxxxxx, krzk@xxxxxxxxxx, hns@xxxxxxxxxxxxx, ebiederm@xxxxxxxxxxxx, dongsheng.qiu@xxxxxxxxxxx, yanfei.li@xxxxxxxxxxx, rick.tyliu@xxxxxxxxxxx, sernia.zhou@xxxxxxxxxxx, zhenwenjin@xxxxxxxxx

Introduce SMP support for MIPS Creator CI20, which is
based on Ingenic JZ4780 SoC.

Follow-Ups:
- [PATCH v8 1/6] MIPS: JZ4780: Introduce SMP support.
  - From: 周琰杰 (Zhou Yanjie)
- [PATCH v8 4/6] dt-bindings: MIPS: Document Ingenic SoCs binding.
  - From: 周琰杰 (Zhou Yanjie)
- [PATCH v8 0/6] Introduce SMP support for CI20 (based on JZ4780).
  - From: 周琰杰 (Zhou Yanjie)
- [PATCH v8 3/6] clocksource: Ingenic: Add high resolution timer support for SMP.
  - From: 周琰杰 (Zhou Yanjie)
- [PATCH v8 2/6] MIPS: CI20: Modify DTS to support high resolution timer for SMP.
  - From: 周琰杰 (Zhou Yanjie)
- [PATCH v8 6/6] MIPS: CI20: Update defconfig to support SMP.
  - From: 周琰杰 (Zhou Yanjie)
- [PATCH v8 5/6] MIPS: Ingenic: Add 'cpus' node for Ingenic SoCs.
  - From: 周琰杰 (Zhou Yanjie)