[U-Boot] dfu: make data buffer size configurable

[Marek Vasut]

Dear Tom Rini,

> On Mon, Jun 10, 2013 at 09:05:48AM +0200, Wolfgang Denk wrote:
> > Dear Heiko Schocher,
> > 
> > In message <51B555D7.5010001 at denx.de> you wrote:
> > > Ok, I can change this. Envvar name "dfu_data_buf_size" is ok?
> > 
> > Such long names are a paint to type. As we can't buffer anything else
> > but data, we should be able to omit this, i. e. what about
> > 
> > 	dfu_bufsiz
> > 
> > ["bufsiz" as used for example as BUFSIZ in C89 stdio.h]
> 
> Works for me.

WFM, but I need to read the discussion around here. I just stopped playing dead 
beetle. Actually, I'm trying to find out why such a variable is needed at all. 
Can the buffer not be allocated dynamically (and thus dependant only on malloc 
area size)?

Please ignore this if it's been answered in one of the emails I didn't read yet.

Best regards,
Marek Vasut