Revert "Update to 3.1.5"

This reverts commit f2473b911e3447bfc14dc539aa0630a01ad053c6.
Revert "Update to 3.1.4"

This reverts commit 98ba5991109d56e3915ccbc7bdb28c4a74e6935e.
Revert "Update to 3.1.3"

This reverts commit c2891153397b0da6d18eba56ff3e7b4f656b2cac.
Revert "Update to 3.1.2"

This reverts commit ffed4a1cfd0a024f817a59b5ec26c3d51d9e76ec.
Add new OpenRISC Architecture
Add new Dynamic Writeback Throttling