eCos + LPC21xx footprint

[Jani Monoses]

>>Which targets need this? I blindly copied it from the AT91 hal.
>>I disabled it now and the app works using the ldr.
>>So if I don't define this switch at all there should be not reset
>>vector differences right? I see that the xscales do not use it either.
> 
> 
> The branch version is position independent. For ROMRAM startups and
> platforms where the ROM is relocated using the MMU, the code is linked
> to the address it will run at after relocation. So it is important it
> doesn't use any absolute references before the relocation is complete.

So what advantage does the ldr version have over the branch one? The one I can think of
is if the reset_vector is more than a branch away (32MB I think).
And I think that for RAM startups the checksum doesn't matter since they're not loaded by 
the onboard loader at start.

Jani