Merge tag 'u-boot-atmel-2021.04-b' of https://gitlab.denx.de/u-boot/custodians/u-boot-atmel

Second set of u-boot-atmel features for 2021.04 cycle

This feature set includes macb updates for all interfaces and new
sama7g5 variant support; micrel ksz9031 DLL support; a new board from
Giant based on Adafruit feather form factor which contains a SAMA5D27
SoC; several fixes regarding the NAND flash PMECC block; and pincontrol
drive strength support for pio4 controller.