arm64: Remove ECC check in do_bad

In previous targets, we would check for ECC errors on do_bad case as
there were forms of ECC that did not generate interrupts. On current
targets, as all forms of ECC raise an interrupt, we no longer need to
make the check.

Change-Id: I406b93f09fd9ce250584c019e9600c2412c935cc
Signed-off-by: Kyle Yan <kyan@codeaurora.org>
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>