Document the bindings for HiKey 970 (hi3670) PCIe PHY
interface, supported via the pcie-kirin driver.
Signed-off-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/461495431dd28ad2779658659f137db4bd747aa8.1628061310.git.mchehab+huawei@kernel.orgSigned-off-by: NRob Herring <robh@kernel.org>