[U-Boot] strtonum() is gawk specific extension

[Vasili Galka]

Hi Simon,

On Wed, Jun 18, 2014 at 9:10 AM, Simon Glass <sjg at chromium.org> wrote:
> I thought of an ugly way and sent a patch using bc, but please let me
> know if you have something better.

I honestly don't know. Is bc considered "standard" and always comes on
Linux systems?
Maybe there shall be a list of prerequisites in README file?
For example some configurations require openssl on the host.

Best,
Vasili