This can be useful for generic scripts. For example, rather than hard-
coding a script to ext2load tegra-harmony.dtb, it could load
${soc}-${board}.dtb and hence not need adjustments to run on multiple
boards.

Signed-off-by: Stephen Warren <[email protected]>
Acked-by: Simon Glass <[email protected]>
Signed-off-by: Tom Warren <[email protected]>