[U-Boot] core ticks/timer code

[Scott McNutt]

> so if we were to document things, it should read like this:
>  - CONFIG_SYS_HZ is required to be 1000

Can't this just be eliminated? It's stupid to have a configurable
option that is neither ;-)

And it doesn't do much for my confidence when things stop working
(like my tftp downloads now that the tftp timeout has been, ahem,
"fixed") only because a "configurable" option wasn't set to the
"correct" value.

If we can't change it with breaking something, then let's stop
kidding ourselves and get rid of it.

--Scott