MAINTAINERS: Switch to Marvell addresses

Switch all addresses from @cavium.com to @marvell.com.

On that occasion, switch also to my Marvell address for all my
Cavium/Marvell entries.

Link: https://lore.kernel.org/r/20191119190436.17875-3-rrichter@marvell.com


Cc: Sunil Goutham <sgoutham@marvell.com>
Cc: George Cherian <gcherian@marvell.com>
Cc: soc@kernel.org
Signed-off-by: Robert Richter <rrichter@marvell.com>
Signed-off-by: Olof Johansson <olof@lixom.net>