Revert "defconfig: apq8084: Disable L2 master port error panic"

Now that L2 master port decode errors are no longer seen,
re-enable the L2 master port decode error panic, to easily
catch such errors surfacing in the future.

This reverts commit 504defc4.

Change-Id: Ib2697a157db6bb28de199fe2843c14857acde085
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>