Update OLPC repository for new drivers

Use OOB Master branch patch 12a6196f7c551ce124945f1b78a02d31093dd744
to use a new 13.2.1 hardware specific frozen repository, which is a
clone of the 13.2.0 with new kernel and firmware only.

Signed-off-by: Martin Abente Lahaye <tch@sugarlabs.org>