Removal of dlmalloc?

[Ahmad Fatoum]

Hi,

We have a TLSF implemenation in barebox for >= 13 years now and it has
more features than dlmalloc like multiple pools and KASAN integration.

I think it's thus time to retire the dlmalloc we inherited from U-Boot.

Unfortunately, TLSF was not the default in the config, even though the
most common configs select it. I'd thus suggest we remove dlmalloc
altogether after v2025.06.0 is tagged.

Thoughts? Objections?

Cheers,
Ahmad