feat(plat/qemu): add sdei support for QEMU

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

Signed-off-by: Dongjiu Geng <gengdongjiu1@gmail.com>
Change-Id: I203732520708a5489e63d009e16d94c1253b99f8
1 file changed