revert: use debug builds for Coverity again

Now that we can choose to build FVP images with up to a 512KB Trusted
SRAM, we can disapply `DEBUG=0` on these Coverity builds again.

Signed-off-by: Chris Kay <chris.kay@arm.com>
Change-Id: Ie2fa1104191c8e32d236940d681fcd0fac2b4a9b
1 file changed