libfdisk: (gpt) add /home GUID

Reported-by: andreas.hanke@gmx-topmail.de
References: http://cgit.freedesktop.org/systemd/systemd/commit/?id=1a14a53cfded6e78c6e8dfb73fdff0039971d642
Signed-off-by: Karel Zak <kzak@redhat.com>