Replace by SYS_BUS_DEVICE() QOM cast macro using a scripted conversion.
Avoids the old macro creeping into new code.

Resolve a Coding Style warning in openpic code.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Cc: Anthony Liguori <anthony@codemonkey.ws>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>