Add nxpmicro-mfgtools to nixpkgs
From the project's homepage [1]:
Freescale/NXP I.MX Chip image deploy tools.
The project's only binary and library at the moment is UUU. NXP
might add more in the future, so making the package name:
nxpmicro-mfgtools
instead of:
nxp-uuu
or something similar.
[1]: https://github.com/NXPmicro/mfgtools
