arm64: add initial support for the Rockchip rk3368

This adds initial support for the new rk3368 ARM64 soc from Rockchip.

Overall it looks like someone dropped some A53 cores into a rk3288, so it shares a lot of peripherals that only differ in details. Therefore stuff like the mmc, usb, spi, i2c controllers work out of the box. The support for the gmac already made it into the merge window as well as the pinctrl support.

Interestingly, in its core the rk3368 seems trying to be a model student with psci for smp and using scpi for ddr frequency scaling, although I currently do not understand how the mailbox works yet. The display controllers also are only minimally different so I'm hopefully to have working graphics in the near-ish future :-)

As mentioned in the dts patch, this series depends on the dt-binding header for the clock ids, so will need a shared branch once this is ready.

changes since v1:
- add missing device_type = "memeory", as found by Mark Rutland
- fix patch subject for patch4 (the board is called R88), found by Naoki Fukaumi

Heiko Stuebner (4):
arm64: add Rockchip architecture entry
arm64: defconfig: enable ARCH_ROCKCHIP
arm64: dts: add Rockchip rk3368 core dtsi and board dts for the r88
board
dt-bindings: document rk3368 R89 board from Rockchip

 Documentation/devicetree/bindings/arm/rockchip.txt |   4 +
 arch/arm64/Kconfig                                 |  10 +
 arch/arm64/boot/dts/Makefile                       |   1 +
 arch/arm64/boot/dts/rockchip/Makefile              |   5 +
 arch/arm64/boot/dts/rockchip/rk3368-r88.dts        | 353 ++++++++
 arch/arm64/boot/dts/rockchip/rk3368.dtsi           | 900 +++++++++++++++++++++
 arch/arm64/configs/defconfig                       |   2 +
 7 files changed, 1275 insertions(+)
 create mode 100644 arch/arm64/boot/dts/rockchip/Makefile
 create mode 100644 arch/arm64/boot/dts/rockchip/rk3368-r88.dts
 create mode 100644 arch/arm64/boot/dts/rockchip/rk3368.dtsi

2.1.4