ci(coverity): add coverage for PLAT_REPORT_CTX_MEM_USE

This patch adds a build config for PLAT_REPORT_CTX_MEM_USE
to tf-cov-make, to ensure that the relevant code and files are scanned.

Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
Change-Id: Ie608b515f332674f63e43467f6c9eb23063ba1a9
1 file changed