huawei-kiwi: readd device (downstream)

Now that there is a "unmaintained" category, readd huawei-kiwi downstream (which got replaced in !1826 (merged)).

Seems to run stable. But when installing ofono and msm-modem-downstream it crashes after ~1min.
Last log in dmesg is the same as https://wiki.postmarketos.org/wiki/Motorola_Moto_G4_(motorola-athene)#Firmware_issues (not sure if this log is related at all)