Staging: move the position of the ipack source line in Kconfig

Moved the ipack source line to the proper place, at the end of the list in the
staging's Kconfig file.

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