ConnectCore 93 DVK only connects the XBee reset line (XBEE_RESET_N_GPIO) but not
the sleep request (XBEE_SLEEP_RQ_GPIO)
It also reworks the 'xbee-init' script to support empty reset
(XBEE_RESET_N_GPIO) or sleep request (XBEE_SLEEP_RQ_GPIO) values.
https://onedigi.atlassian.net/browse/DEL-8375
Signed-off-by: Tatiana Leon <Tatiana.Leon@digi.com>