MAINTAINERS: add myself as bootdevice.c maintainer

bootdevice.c was created by me, and I wrote most of
the code in this file. And now I can maintain it,
I'd hope nobody object this.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
MAINTAINERS: add section for QEMU Guest Agent

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Add Migration maintainer

Signed-off-by: Juan Quintela <quintela@trasno.org>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Merge remote-tracking branch 'remotes/armbru/tags/for-upstream' into staging

Patches to MAINTAINERS that haven't been picked up

# gpg: Signature made Tue 11 Nov 2014 08:46:55 GMT using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"

* remotes/armbru/tags/for-upstream:
  Add Migration maintainer
  MAINTAINERS: add section for QEMU Guest Agent
  MAINTAINERS: add myself as bootdevice.c maintainer

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>