ARM fix for big endian linux-elf targets

[Paul Brook]

> > We want a big-endian toolchain
> > with a little-endian multilib to work (and vice-versa).
>
> I don't see why one would need a mix of big and little endian
> toolchains ;-)

Because it's nice to have a single toolchain that can support multiple target 
boards. That's the whole point of multilibs. Ideally we'd be able to build a 
single compiler that could (with suitable multilibs) build for any arm 
target. As someone while distributes and supports toolchains it's a pain 
having to have different toolchains for linux, uclinux, SymbianOS, bare elf, 
big endian, little endian, etc.

Paul