cirrus: cs89x0: Code style neatening

Neaten the comments and reflow the code without
changing anything other than whitespace.

git diff -w shows just comment neatening and a few
line removals.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>