MAINTAINERS: update email
Brandon is no longer at Red Hat. Use a different email.
# Please keep the list sorted.
# MAINTAINERS
-Brandon Philips <bphilips@redhat.com> (@philips) pkg:*
+Brandon Philips <brandon@ifup.org> (@philips) pkg:*
Gyuho Lee <gyuhox@gmail.com> <leegyuho@amazon.com> (@gyuho) pkg:*
Hitoshi Mitake <h.mitake@gmail.com> (@mitake) pkg:*
Jingyi Hu <jingyih@google.com> (@jingyih) pkg:*
