* Backport USB PCIe/XHCI patches to U-Boot 2020.07
Backport relevant patches required to make PCIe/USB XHCI work.
* Backport/integrate PCIe device tree changes from upstream Linux
U-Boot uses the device tree provided by upstream Linux. Make sure the
device tree has the relevant chanages to make VL805 USB controller
reset work.
* Document RPi 4 USB mass storage support (#746)
Unfortunately builds for 32-bit seem to lead to freezes. Conservatively
only update to 2020.07 for 64-bit builds.
Co-authored-by: Malcolm Lashley <mlashley@gmail.com>
Co-authored-by: Malcolm Lashley <mlashley@gmail.com>
