[PATCH openbmc] Add flash copy commands to busybox

[Stewart Smith]

OpenBMC Patches <openbmc-patches at stwcx.xyz> writes:
> From: "Milton D. Miller II" <miltonm at us.ibm.com>
>
> The flashcp command will copy a file to a mtd device after erasing the
> partition.   This is useful for updating the bmc u-boot, kernel,
> environment, and/or initrd.  It can also be used for upating the whole
> pnor, or partitions if we later add ffs partition parsing.

FYI, I'm going to add FFS partitioning to pflash (for creating/editing
partitions) and then we can just use it everywhere (during build of pnor
image, on BMC and on host).

This should (in total) be a few tens of thousands LoC less.