Documentation/features: Remove unicore32 from kcov and kmemleak

Commit 3839a746 ("Documentation/features: Add kcov") and
commit 4641961c ("Documentation/features: Add kmemleak") were added
shortly after the unicore32 port was removed in commit fb37409a
("arch: remove unicore32 port"). Remove the unicore32 feature lines from
kcov and kmemleak as well.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Link: https://lore.kernel.org/r/20200707090922.4746-1-tklauser@distanz.ch


Signed-off-by: Jonathan Corbet <corbet@lwn.net>