docker: remove debian8-mxe definitions

We don't have a debian8-mxe dockerfile anymore.

Fixes: 67bd36b
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190923181140.7235-2-jsnow@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

tests/docker/Makefile.include

@@ -7,7 +7,7 @@ DOCKER_FILES_DIR := $(SRC_PATH)/tests/docker/dockerfiles
 DOCKER_DEPRECATED_IMAGES := debian
 # we don't run tests on intermediate images (used as base by another image)
 DOCKER_PARTIAL_IMAGES := debian debian8 debian9 debian10 debian-sid
-DOCKER_PARTIAL_IMAGES += debian8-mxe debian9-mxe debian-ports debian-bootstrap
+DOCKER_PARTIAL_IMAGES += debian9-mxe debian-ports debian-bootstrap
 DOCKER_IMAGES := $(filter-out $(DOCKER_DEPRECATED_IMAGES),$(sort $(notdir $(basename $(wildcard $(DOCKER_FILES_DIR)/*.docker)))))
 DOCKER_TARGETS := $(patsubst %,docker-image-%,$(DOCKER_IMAGES))
 # Use a global constant ccache directory to speed up repetitive builds