cpumask: Use accessors code.: sparc64

Impact: use new API

Use the accessors rather than frobbing bits directly.  Most of this is
in arch code I haven't even compiled, but is straightforward.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>

diff --cc arch/sparc/kernel/mdesc.c
Simple merge

diff --cc arch/sparc/kernel/prom_64.c
Simple merge