blackfin: fix up obsolete cpu function usage.
blackfin: fix up obsolete cpu function usage.

Signed-off-by: Rusty Russell <df9728c9e5104131c08c7adb03af425394842596@rustcorp.com.au>
Cc: Steven Miao <eb4bb6630d9afd913be5ae87090c50ac1ba7a4b2@gmail.com>
Cc: b3a054fb717215ae350d917c4717868d9c01cc12@lists.sourceforge.net

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs