Removing "fdt_high=0xffffffff" from board environments

Hey all,

Relatively recently it's been highlighted that a number of boards are disabling relocation of the device tree image in memory and this in turn leading to various difficult to resolve bugs. At heart, disabling device tree relocation at boot is something that should be used in rare circumstances (and more generally fdt_high / initrd_high set to where they are already residing in memory, as a known, correct and aligned address).

I would like to ask everyone to update their board config file to use the bootm_size (or set CONFIG_SYS_BOOTMAPSZ) to the amount of memory (size, not location) available to safely contain a kernel, device tree and initrd for relocation. Thanks all!