kvic-z

I found mainline kernel lacks support for DDR DVFS, but found that Rockchip has provided generic SDRAM initialisation in u-boot. It'll be great if Rockchip or @FireflyTeam can provide one...

Tested on Ryzen 3600 and verified against motherboard UEFI, and HWiNFO64 on Windows Also added in a couple misc changes.