Blackfin: unify memory map headers

Many aspects of the Blackfin memory map is exactly the same across all
variants.  Rather than copy and paste all of these duplicated values in
each header, unify all of these into the common Blackfin memory map header
file.  In the process, push down BF561 SMP specific stuff to the BF561
specific header to keep the noise down.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>