ARM: Devicetree material for 5.14

Like always, the DT branch is sizable. There are numerous additions and
fixes to existing platforms, but also a handful of new ones introduced.
Less than some other releases, but there's been significant work on
cleanups, refactorings and device enabling on existing platforms.

A non-exhaustive list of new material:

 - Refactoring of BCM2711 dtsi structure to add support for the Raspberry Pi 400
 - Rockchip: RK3568 SoC and EVB, video codecs for rk3036/3066/3188/322x
 - Qualcomm: SA8155p Automotive platform (SM8150 derivative),
   SM8150/8250 enhancements and support for Sony Xperia 1/1II and 5/5II
 - TI K3: PCI/USB3 support on AM64-sk boards, R5 remoteproc definitions
 - TI OMAP: Various cleanups
 - Tegra: Audio support for Jetson Xavier NX, SMMU support on Tegra194
 - Qualcomm: lots of additions for peripherals across several SoCs, and
   new support for Microsoft Surface Duo (SM8150-based), Huawei Ascend G7.
 - i.MX: Numerous additions of features across SoCs and boards.
 - Allwinner: More device bindings for V3s, Forlinx OKA40i-C and NanoPi
   R1S H5 boards
 - MediaTek: More device bindings for mt8167, new Chromebook system
   variants for mt8183
 - Renesas: RZ/G2L SoC and EVK added
 - Amlogic: BananaPi BPI-M5 board added