net: yaip: Start to use logging macros from sys_log.h

Instead of directly calling printk/printf, the network printing
macros will use syslog macros defined in sys_log.h

Change-Id: I3f12f81557f50b24ca47a43f345162f9ffbd574c
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>