MAINTAINERS: Add maintainer for xilinx-ams

Add maintaner entry for xilinx-ams driver.

Signed-off-by: Anand Ashok Dumbre <anand.ashok.dumbre@xilinx.com>
Link: https://lore.kernel.org/r/20211203212358.31444-6-anand.ashok.dumbre@xilinx.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>