fix(tf-coverity): remove stale file from ignore list

The "io_dummy" driver was removed from TF-A source tree a few months
ago [1]. Thus, remove its source file from Coverity's list of files to
ignore.

[1] TF-A commit 63e0b865382eb82 "chore(io): remove io_dummy driver"

Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
Change-Id: Ic8a8bf8e18495d47242b03532d3eb0c29bd64a4a
1 file changed