Merge tag 'u-boot-amlogic-20210419' of https://source.denx.de/u-boot/custodians/u-boot-amlogic

- fix Ethernet on Odroid-C2 by re-adding old bindings style PHY reset
- add G12A PCIe clock gates
- add G12A PCIe PHY OPs
- enable PCIe for Khadas VIM3/VIM3L boards DT
- enable PCIe and NVME for Khadas VIM3/VIM3L boards config
- update Amlogic board documentation for PCIe support