Input: serio - fix sysfs layout

Restore previous layout of sysfs attributes that was broken by commit
3778a212 (input: serio: remove bus usage of
dev_attrs) which moved all serio device attributes into 'id' group, when
only 'type', 'proto', 'id', and 'extra' should be in 'id' group and the
rest of attributes should be attached directly to the device.

Reported-by: Thomas Hellstrom <thellstrom@vmware.com>
Tested-by: Thomas Hellstrom <thellstrom@vmware.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>