calimain: Update maintainers and their email addresses

Signed-off-by: Christian Riesch <christian@riesch.at>
Cc: Manfred Rudigier <manfred.rudigier@omicronenergy.com>
Cc: Christoph Rüdisser <christoph.ruedisser@omicronenergy.com>

board/omicron/calimain/MAINTAINERS

 CALIMAIN BOARD
-M:	Manfred Rudigier <manfred.rudigier@omicron.at>
-M:	Christian Riesch <christian.riesch@omicron.at>
+M:	Manfred Rudigier <manfred.rudigier@omicronenergy.com>
+M:	Christoph Rüdisser <christoph.ruedisser@omicronenergy.com>
 S:	Maintained
 F:	board/omicron/calimain/
 F:	include/configs/calimain.h