makefiles/Makefile.kicad: fix dependency bugs
makefiles/Makefile.kicad: fix dependency bugs

- Makefile.kicad (fab-pcb): add explicit dependency instead of "gerber"
- Makefile.kicad (fab-smt): depend on all files, not just the .csv files
- Makefile.kicad (clean): also remove $(NAME)-bom.csv

cfriedt/ben-wpan,cfriedt/ben-wpan,cfriedt/ben-wpan,cfriedt/ben-wpan,cfriedt/ben-wpan,cfriedt/ben-wpan