MAINTAINERS: Update Broadcom RDMA maintainers

Updating the bnxt_re maintainers as Naresh decided to leave Broadcom.

Link: https://lore.kernel.org/r/1631709163-2287-13-git-send-email-selvin.xavier@broadcom.com


Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>