[BUILD-CONFIGURATOR][FLAVOUR] Add post-scripts execution, improve flavours menu

• Fixed configurator launcher (seco-setup.sh) to handle the customs in CleaOS 2.0 as their layers will be in the folder meta-seco.
• Add favours to Yconfig
• Add the feature that run the post-scripts after the build environment has been created: When creating or reconfiguring a build environment (respectively with ./seco-setup.sh -c and ./seco-setup.sh -r) the post-scripts found in the hardware-related and flavour-related layers are executed.

The scripts are executed in source mode so they can modify the environment.

The scripts are searched with the pattern *-seco-<flavour>-post-script.sh for flavour and *-seco-<arch>-post.script.sh for Seco's SOC layer.

The scripts are execute in alphabetical order: to guarantee the correct execution order it is possible to name the scripts as follow assuming the flavour is clea-os-things: 0001-seco-clea-os-things-post-script.sh, 0002-seco-clea-os-things-post-script.sh, etc..

For the hardware layer, assuming a build for Rockchip-base boards: 0001-seco-rk-post-script.sh, 0002-seco-rk-post-script.sh, etc..

The scripts can be placed wherever in the layer as the configurator will scan the full directory but it's suggested to place them in the "conf" folder to keep the layers clean.

• Bump seco-build-configurator to version v1.2.0.

Signed-off-by: Nicola Sparnacci nicola.sparnacci@seco.com