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

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

This feature set includes the new board SAMA7G5 EK, the new evaluation
kit for Microchip AT91 SAMA7G5 SoC . The current board support includes
two configurations for booting from eMMC (SDMMC0), SD-Card (SDMMC1), and
support for two Ethernet interfaces.