doc: release-notes-2.3: Add ADXL345 mention
doc: release-notes-2.3: Add ADXL345 mention

A 3-axis accelerometer from Analog Devices.

Signed-off-by: Piotr Zierhoffer <e1d19b12230bfc9d1ee7dc1e438ebc847bc06dad@antmicro.com>

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