[U-Boot] reset environment

[Dexdyne Postmaster]

In development, it's a bit of a pain that installing a new u-boot image
with different settings for bootargs and bootcmd doesn't actually change
anything, because the environment in flash is still valid.

Worse, there doesn't seem to be a command to say "over-write that with
your new defaults"

If that is indeed so, then can I propose such a command should be added?

I'll try to knock out the patch if no-one more skilled wants to leap into
action!
David Collier

www.dexdyne.com