net: sunhme: Switch SBUS to devres

The PCI half of this driver was converted in commit 914d9b27 ("sunhme:
switch to devres"). Do the same for the SBUS half.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>