[U-Boot] [patch] make hello world example work for at91sam9261ek and make readme clearer about this

[Remy Bohmer]

Hello Jean-Christophe,

>> @@ -33,9 +33,13 @@ ifeq ($(ARCH),arm)
>>  ifeq ($(BOARD),omap2420h4)
>>  LOAD_ADDR = 0x80300000
>>  else
>> +ifeq ($(BOARD),at91sam9261ek)
>> +LOAD_ADDR = 0x21400000
>> +else
>>  LOAD_ADDR = 0xc100000
>>  endif
>>  endif
>> +endif
> Honestly I'll prefer to remove all arch and board ifdef
> and let the board ovewrite it or the arch if the board do not not already define it
> and do here
> LOAD_ADDR ?= <default addr>

I completely agree about this.
This was just a minor patch I had on the stack for months and
yesterday I just put them all out.
The most important part of this patch was the comment about the
load-addr in the readme file.
Frequently questions misunderstandings about the examples appear on
the ML, and the readme change would help there.

I can look into it later on to improve it and find a more generic
solution. In the mean time, I do not think this patch hurts anyone ;-)

Remy

>
> Best Regards,
> J.
>