There seems to be a difference in firmware calling convention
between upstream and NXP kernels. On some cpus like ls1028
it will hang on firmware secure get random when using LF uboot
with upstream kernel. Instead of commenting it out, don't call
get radnom seed when "kaslr-seed" is not present in device tree.
Signed-off-by: Wojciech Dubowik <Wojciech.Dubowik@protonmail.ch>