setup-environment-internal: show full layer path when listing machines or distros
setup-environment-internal: show full layer path when listing machines or distros

When listing available MACHINEs or DISTROs during environment setup, we are only
showing the first element in the layer path. When using a repo with several
layers inside it, it might be more convenient to show the full path of the
layer.

For example, if we were to show machines from meta-linaro repo of layers, before
this patch we would see:

genericarmv7ab      meta-linaro
genericarmv7a       meta-linaro
genericarmv8b       meta-linaro
genericarmv8-ilp32  meta-linaro
genericarmv8        meta-linaro

and now, we can see:

genericarmv7ab      meta-linaro/meta-linaro
genericarmv7a       meta-linaro/meta-linaro
genericarmv8b       meta-linaro/meta-aarch64
genericarmv8-ilp32  meta-linaro/meta-ilp32
genericarmv8        meta-linaro/meta-aarch64

Change-Id: I8ca35b100e2411db7f90c694c1083dba44739797
Signed-off-by: Nicolas Dechesne <05fca36dfcf68f7e1c9eaf62b074676ab50a133b@linaro.org>

ndechesne/qcom-oe-manifest,linaro-home/lhg-oe-manifests,96boards/oe-rpb-manifest