MAINTAINERS: Update maintainer of Amazon EFA driver

Change EFA driver maintainer from Gal Pressman to myself. Keep Gal as a
reviewer at his request.

Link: https://lore.kernel.org/r/20230525094444.12570-1-mrgolin@amazon.com


Signed-off-by: Michael Margolin <mrgolin@amazon.com>
Acked-by: Gal Pressman <gal.pressman@linux.dev>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>