Merge tag 'u-boot-rockchip-20200531' of https://gitlab.denx.de/u-boot/custodians...

- Fix mmc of path after syncfrom kernel dts;
- Add dwc3 host support with DM for rk3399;
- Add usb2phy and typec phy for rockchip platform;
- Migrate board list doc to rockchip.rst;
- Add rk3399 Pinebook Pro board support;
- Update dram_init in board_init and add memory node in SPL;