MAINTAINERS: update my email address

I'm leaving my job at Red Hat, this email address will stop working next week.
Update it to one that I will have access to later.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Message-Id: <1486120433-11628-1-git-send-email-amit.shah@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

MAINTAINERS

@@ -1034,7 +1034,7 @@ F: hw/input/virtio-input*.c
 F: include/hw/virtio/virtio-input.h
 
 virtio-serial
-M: Amit Shah <amit.shah@redhat.com>
+M: Amit Shah <amit@kernel.org>
 S: Supported
 F: hw/char/virtio-serial-bus.c
 F: hw/char/virtio-console.c
@@ -1043,7 +1043,7 @@ F: tests/virtio-console-test.c
 F: tests/virtio-serial-test.c
 
 virtio-rng
-M: Amit Shah <amit.shah@redhat.com>
+M: Amit Shah <amit@kernel.org>
 S: Supported
 F: hw/virtio/virtio-rng.c
 F: include/hw/virtio/virtio-rng.h