drivers: wifi: Update debug level of wakeup source dump function

Update wakeup source dump function to DBG level. This function will
print and clear wakeup source registers of NXP wifi chips with
CONFIG_WIFI_LOG_LEVEL_DBG enabled. By changing debug level of this file,
user can avoid wakeup source clear.

Signed-off-by: Hui Bai <hui.bai@nxp.com>