beaglebone-green-wifi.coffee: Change version to yocto-morty instead of yocto-jethro
beaglebone-green-wifi.coffee: Change version
to yocto-morty instead of yocto-jethro

We now switch to yocto morty

Signed-off-by: Florin Sarbu <3a837a37a2ac9072a088641ec330e0e5d5b86f4e@resin.io>

resin-os/resin-beaglebone,resin-os/resin-beaglebone