MAINTAINERS: NTB: Update contact info

I am no longer employed by Dell EMC.  For the purposes of NTB driver
development and maintenance, please contact me via my personal email.

Signed-off-by: Allen Hubbe <[email protected]>
Signed-off-by: Allen Hubbe <[email protected]>
Signed-off-by: Jon Mason <[email protected]>

Author: Allen Hubbe

MAINTAINERS

@@ -9708,7 +9708,7 @@ F:	drivers/ntb/hw/amd/
 NTB DRIVER CORE
 M:	Jon Mason <[email protected]>
 M:	Dave Jiang <[email protected]>
-M:	Allen Hubbe <Allen.Hubbe@emc.com>
+M:	Allen Hubbe <allenbh@gmail.com>
 L:	[email protected]
 S:	Supported
 W:	https://github.com/jonmason/ntb/wiki