Merge tag 'xilinx-for-v2020.10-rc3' of https://gitlab.denx.de/u-boot/custodians/u-boot-microblaze

Xilinx changes for v2020.10-rc3

- Fix fdtfile variable setup
- Fix bootm_*/fdt_high/initrd_high variables handling
- Fix Kconfig dependencies for Xilinx drivers
- Fix booting u-boot from lowest memory
- Fix firmware payload argument count for Versal
- Fix dfu configurations
- Fix mio_bank property handling
- Fix and align code around ID detection
- Start to use ENV_VARS_UBOOT_RUNTIME_CONFIG
- Simplify logic around reading MAC from eeprom
- Decrease malloc length for zynqmp mini qspi
- Enable preboot for ZynqMP and Versal

i2c:
- Fix i2c eeprom partitions handling

mmc:
- Fix logic around HS mode enabling and use proper functions