Introduce SMP support for CI20 (based on JZ4780) v2.

Subject: Introduce SMP support for CI20 (based on JZ4780) v2.
From: 周琰杰 (Zhou Yanjie) <zhouyanjie@xxxxxxxxxxxxxx>
Date: Fri, 17 Jan 2020 01:23:42 +0800
Cc: linux-kernel@xxxxxxxxxxxxxxx, devicetree@xxxxxxxxxxxxxxx, mips-creator-ci20-dev@xxxxxxxxxxxxxxxx, robh+dt@xxxxxxxxxx, paul.burton@xxxxxxxx, paulburton@xxxxxxxxxx, jhogan@xxxxxxxxxx, mark.rutland@xxxxxxx, syq@xxxxxxxxxx, ralf@xxxxxxxxxxxxxx, rick.tyliu@xxxxxxxxxxx, jason@xxxxxxxxxxxxxx, keescook@xxxxxxxxxxxx, geert+renesas@xxxxxxxxx, krzk@xxxxxxxxxx, paul@xxxxxxxxxxxxxxx, prasannatsmkumar@xxxxxxxxx, sernia.zhou@xxxxxxxxxxx, zhenwenjin@xxxxxxxxx, ebiederm@xxxxxxxxxxxx, hns@xxxxxxxxxxxxx, paul@xxxxxxxxxxxxx

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

Follow-Ups:
- [PATCH v2 1/6] MIPS: JZ4780: Introduce SMP support.
  - From: 周琰杰 (Zhou Yanjie)
- [PATCH v2 0/6] Introduce SMP support for JZ4780.
  - From: 周琰杰 (Zhou Yanjie)
- [PATCH v2 5/6] MIPS: CI20: Modify DTS to support high resolution timer for SMP.
  - From: 周琰杰 (Zhou Yanjie)
- [PATCH v2 2/6] clocksource: Ingenic: Add high resolution timer support for SMP.
  - From: 周琰杰 (Zhou Yanjie)
- [PATCH v2 3/6] dt-bindings: MIPS: Document Ingenic SoCs binding.
  - From: 周琰杰 (Zhou Yanjie)
- [PATCH v2 6/6] MIPS: CI20: Update defconfig to support SMP.
  - From: 周琰杰 (Zhou Yanjie)
- [PATCH v2 4/6] MIPS: Ingenic: Add 'cpus' node for Ingenic SoCs.
  - From: 周琰杰 (Zhou Yanjie)