Integrate meta-seco-bsp/ap/fix-bbfiles-dynamic

Commit: edgehog/layers/seco/meta-seco-bsp@246a8ad8

[LAYER] do not set BBFILES_DYNAMIC to ""

Remove this assignment from local.conf: BBFILES_DYNAMIC = ""

Which makes other layers not parse the files in their dynamic-layers/ dir when this layer is included (e.g. embedded on raspberrypi)