Revert "Revert "Absorb dho_gcc.xml into default""

This reverts commit 08e88ed75dcc5692ce8a18d51925d26dcb0d039f.
Revert "Revert "use a few linaro repos that have changed since we tracked them""

This reverts commit 258e5a734bddca7b7cd40dd8eba6629e7bfa928a.