Documentation: arm: marvell: Extend Avanta list

Include another two SoCs from Avanta family.

Signed-off-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20220121115804.28824-1-pali@kernel.org


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