bcm2835-bootfiles: tighten up dep on rpi-config
Intuitively, bcm2835-bootfiles:do_deploy should depend on rpi-config:do_deploy.
This indirectly resolves a missing dep between rpi-config:do_deploy and
do_image_rpi_sdimg (on an image recipe inheriting from sdcard_image-rpi.bbclass).
This manifested as changes to rpi-config (e.g. setting or unsetting
ENABLE_* variables) not triggering a rebuild of the SD card image.
Signed-off-by: Chris Laplante <mostthingsweb@gmail.com>