powerpc/ps3: Fix memory leak in device init

Free dynamically allocated device data structures when device registration
fails.  This fixes memory leakage when the registration fails.

Signed-off-by: Masakazu Mokuno <mokuno@sm.sony.co.jp>
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>