Staging: One Laptop Per Child: fix SPDX-License-Identifier issue

Add SPDX-License-Identifier to the source files.
Remove redundant, old license.

Signed-off-by: Arkadiusz Lis <areklis909@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>