fix(tf-cov-make): modify failing build option to DEBUG=0

Currently one build failures due to bl31 image overflow is causing
coverity loss in CI, So disable DEBUG builds for them temporarily
until we get a fix in place.

Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
Change-Id: I1a8a459e491463b3145c4da6572db7753570820a
1 file changed