UniPhier SoC updates for v2020.04 (2nd)
Denali NAND driver changes:
- Set up more registers in denali-spl for SOCFPGA
- Make clocks optional
- Do not assert reset signals in the remove hook
- associate SPARE_AREA_SKIP_BYTES with DT compatible
- switch to UCLASS_MTD
UniPhier platform changes:
- fix a bug in dram_init()
- specify loadaddr for "source" command