[ECOS] Port to XScale board

[Cristiano Ligieri Pereira]

> Try stepping through the code.  Time to learn to use GDB :-)

At last it's working fine now. Well, at least I can execute the simple
Hello World application from Redboot.

That problem was on the macros ICACHE_INVALIDATE_ALL() and
DCACHE_INVALIDATED_ALL() that are not working properly and that are called
right before Redboot transfers the execution control to the application.

Now I guess that the next step is to clean up all the unnecessary code and
fix the non-working ones to generate a ROM version of RedBoot.

Cristiano.