MAINTAINERS: Drop myself as VT-d maintainers

MAINTAINERS: Drop myself as VT-d maintainers

Due to my own limitation on bandwidth, I noticed that unfortunately I won't
have time to review VT-d patches at least in the near future.  Meanwhile I
expect a lot of possibilities could actually happen in this area in the
near future.

To reflect that reality, I decided to drop myself from the VT-d role.  It
shouldn't affect much since we still have Jason around like usual, and
Michael on top.  But I assume it'll always be good if anyone would like to
fill this role up.

I'll still work on QEMU.  So I suppose anyone can still copy me if one
thinks essential.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20240118091035.48178-1-peterx@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Jason Wang <jasowang@redhat.com>