dict_2_md implicitly relies on the tests all having the same order for
their dict keys during printing. This works well with all the tests read
from the .ekl log file but does not work with the "artificial" SPURIOUS
test entries, which end up having their keys in a different order.

Fix the keys order to fix .md printing.

Signed-off-by: Vincent Stehlé <vincent.stehle@arm.com>