Beacon config function writes beacon to hw one write per byte. This is very
slow (usually taking more than 100ms to finish) and causes high CPU usage
when in AP-mode (kworker at ~50% on Intel Atom N270). By batching commands
together zd_mac_config_beacon() runtime can be lowered to 1/5th and lower
CPU usage to saner levels (<10% on Atom).
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi> Signed-off-by: John W. Linville <linville@tuxdriver.com>