Fix for issue #317.

Created by: silabs-oysteink

Controller was checking toplevel OBI signals when checking for allowed interrupts/debug. This causes issued when the write buffer accepted writes before the data_gnt_i was asserted.

Fix is to look at trans_ signals inside the LSU, before the MPU. Added a "interruptible" outout from the LSU instead of looking at lsu_en i ex/wb inside the controller.

Signed-off-by: Oystein Knauserud Oystein.Knauserud@silabs.com