samples: net: lwm2m_client: Add support for MG100 board
samples: net: lwm2m_client: Add support for MG100 board

Add support to build sample for MG100 board.

Signed-off-by: Ryan Erickson <445db09b136432317bdbb8e4308a30651390c2e2@lairdconnect.com>

zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,galak/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr