MAINTAINERS: add entry for Altera mSGDMA

MAINTAINERS: add entry for Altera mSGDMA

This entry is for the standalone driver in drivers/dma/altera-msgdma.c
Add myself as 'Odd fixes' maintainer for this driver as i am currently
writing new code and have access to the hardware.
Add Stefan Roese as reviewer.

Signed-off-by: Olivier Dautricourt <olivier.dautricourt@orolia.com>
Acked-by: Stefan Roese <sr@denx.de>
Phone: (+49)-8142-66989-51 Fax: (+49)-8142-66989-80 Email: sr@denx.de
Link: https://lore.kernel.org/r/4258cb93e0f7ff57c4e116c3e8cd9a1a3159cec6.1623251990.git.olivier.dautricourt@orolia.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>