sync cdctl driver with cdnet 0b3b89b

- cdctl_it: make the state machine entry atomic, drop int_irq from cdctl_dev_init
- cdctl(_it): add idle_wait_len to config, clamp baud divider via clip()
- cd_utils: DIV_ROUND_CLOSEST: fix for negative divisors
- move debug macros to utils/cd_debug.h, debug_config.h keeps arch_dbg_tx only
- arch_wrapper: add delay_us()
- app_main: put the required delay right before cdctl_dev_init
