Merge tag 'u-boot-atmel-fixes-2021.01-a' of https://gitlab.denx.de/u-boot/custodians/u-boot-atmel

First set of u-boot-atmel fixes for 2021.01 cycle:

This specific feature set includes the patches for DT required to fix
the warnings for newer DTC version (1.6.0+), i2c and spi bus unit
address.