The 1st level trap handler jumps to the 2nd level trap handler on
context save requests or regular traps if (mode.debug_en
&& !status.halt) is true.
If we return from the 2nd level trap handler without status.halt=1, then
we need to make sure mode.debug_en is cleared, or we will re-enter the
2nd level trap handler again and again when trapsts.savectx is set.
Change-Id: I4db6369de8c91a32842f488a4df5c9d94fa65aa9
Laurent Morichetti
584ef1e1ca