Merge branch 'newsoc/cix-p1' into soc/newsoc

Patches from Peter Chen <peter.chen@cixtech.com>:

Cixtech P1 (internal name sky1) is high performance generic Armv9 SoC.
Orion O6 is the Arm V9 Motherboard built by Radxa. You could find brief
introduction for SoC and related boards at:
https://radxa.com/products/orion/o6#overview

Currently, to run upstream kernel at Orion O6 board, you need to
use BIOS released by Radxa, and add "clk_ignore_unused=1" at bootargs.
https://docs.radxa.com/en/orion/o6/bios/install-bios

In this series, we add initial SoC and board support for Kernel building.
Since mailbox is used for SCMI clock communication, mailbox driver is added
in this series for the minimum SoC support.

Patch 1-2: add dt-binding doc for CIX and its sky1 SoC
Patch 3: add Arm64 build support
Patch 4-5: add CIX mailbox driver which needs to support SCMI clock protocol.
Patch 6: add Arm64 defconfig support
Patch 7-8: add initial dts support for SoC and Orion O6 board
Patch 9: add MAINTAINERS entry

* newsoc/cix-p1:
  MAINTAINERS: Add CIX SoC maintainer entry
  arm64: dts: cix: Add sky1 base dts initial support
  dt-bindings: clock: cix: Add CIX sky1 scmi clock id
  arm64: defconfig: Enable CIX SoC
  mailbox: add CIX mailbox driver
  dt-bindings: mailbox: add cix,sky1-mbox
  arm64: Kconfig: add ARCH_CIX for cix silicons
  dt-bindings: arm: add CIX P1 (SKY1) SoC
  dt-bindings: vendor-prefixes: Add CIX Technology Group Co., Ltd.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --cc Documentation/devicetree/bindings/vendor-prefixes.yaml
Simple merge

diff --cc MAINTAINERS
Simple merge

diff --cc arch/arm64/Kconfig.platforms
Simple merge

diff --cc arch/arm64/configs/defconfig
Simple merge

diff --cc drivers/mailbox/Kconfig
Simple merge

diff --cc drivers/mailbox/Makefile
Simple merge