Staging: ipack: remove board_name and bus_name fields from struct ipack_device

Removed board_name and bus_name fields from struct ipack_device that are
completely useless.

Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>