CONFIG_BOARD_MRMT_WIRELESS_ZB is not available for thedefaultarchitecture x86.
Result is shown for architecture avr32
default or selected kernelversion does not have config value CONFIG_BOARD_MRMT_WIRELESS_ZB.
Result is shown for kernelversion 6.5.1

Use ZigBee/802.15.4 Module

configname: CONFIG_BOARD_MRMT_WIRELESS_ZB

Wireless Module on ttyS2
└─>Use ZigBee/802.15.4 Module
In linux kernel since version 2.6.31 (release Date: 2009-09-09)