Merge tag 'u-boot-atmel-2020.04-a' of https://gitlab.denx.de/u-boot/custodians/u-boot-atmel

First set of u-boot-atmel features for 2020.04 cycle

This feature set is a patch series from Tudor Ambarus which includes
parsing of the spi flash SFDP parser for SST flashes, and using those
tables to retrieve unique saved per device MAC address. This is then
used as base mac address on the SAMA5D2 Wireless SOM EK board.