stmhal: Put debug builds in separate dir
stmhal: Put debug builds in separate dir

Signed-off-by: Sven Wegener <18dc2ed701c57df81c0b5498c13767c232eb398f@stealer.net>

swegener/micropython,swegener/micropython,swegener/micropython,swegener/micropython,swegener/micropython