Revert "Build with new encore-omap3-3.0.y kernel branch"

We'd like to cut a stable release from this branch, but 3.0.101 has
unresolved problems with the USB subsystem.  Build with the older,
proven 3.0.8 instead for the stable release.

This reverts commit 39850aadaf698ef290a1cfdd81d1bd62670ce51a.

Change-Id: Ifefd6db6fc5342d15c92e9b35530af17b78850bc