MAINTAINERS: update maintainer list for AMD NTB driver

updating with my email address.

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

MAINTAINERS

@@ -11861,6 +11861,7 @@ F:	scripts/nsdeps
 F:	Documentation/core-api/symbol-namespaces.rst
 
 NTB AMD DRIVER
+M:	Sanjay R Mehta <sanju.mehta@amd.com>
 M:	Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
 L:	linux-ntb@googlegroups.com
 S:	Supported