MAINTAINERS: remove Brandon Philips @philips

I haven't been active for quite some time in this project so it is time
to step down.

Thanks everyone!

Signed-off-by: Brandon Philips <brandon@ifup.org>

MAINTAINERS

@@ -1,5 +1,4 @@
 Aaron Lehmann <aaronl@vitelus.com> (@aaronlehmann)
-Brandon Philips <brandon.philips@coreos.com> (@philips)
 Brendan Burns <bburns@microsoft.com> (@brendandburns)
 Derek McGowan <derek@mcgstyle.net> (@dmcgowan)
 Jason Bouzane <jbouzane@google.com> (@jbouzane)