There's no reason to keep the soundhw table in arch_init.c. Move
that code to a new hw/audio/soundhw.c file.

While moving the code, trivial coding style issues were fixed.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20170508205735.23444-2-ehabkost@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>