Change poky submodule to use our github hosted mirror
Change poky submodule to use our github hosted mirror

We do this change because we noticed frequent timeouts
in different parts of our build infrastructure when pulling
the poky repository from https://git.yoctoproject.org/git/poky

Changelog-entry: Change the poky submodule to our github mirror
Signed-off-by: Florin Sarbu <3a837a37a2ac9072a088641ec330e0e5d5b86f4e@balena.io>

resin-os/resin-intel