MAINTAINERS: Update AMD NTB maintainers

Sanju is no longer with AMD. Update the MAINTAINERS file record.

Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

Author: Shyam Sundar S K

MAINTAINERS

@@ -16820,7 +16820,6 @@ F:	Documentation/core-api/symbol-namespaces.rst
 F:	scripts/nsdeps
 
 NTB AMD DRIVER
-M:	Sanjay R Mehta <sanju.mehta@amd.com>
 M:	Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
 L:	ntb@lists.linux.dev
 S:	Supported