cleaner & greener (was Re: A patch for RTEMS4.10.0 PowerPC heap space initialization)

[Kate Feng]

The PR is at http://rtems.org/bugzilla/show_bug.cgi?id=1797
Thanks for all the feedback. I am glad that the API is more or
less verified. Previously, I could not decide where to place the macro.

#define CONFIGURE_MALLOC_BSP_SUPPORTS_SBRK

The patch for the mvme5500 BSP is updated as well at
http://www.rtems.org/bugzilla/show_bug.cgi?id=1786

Cheers,
Kate