doc: releases: added reset controller in release notes 3.1
doc: releases: added reset controller in release notes 3.1

added reset controller in release notes 3.1

Signed-off-by: Andrei-Edward Popa <23ebf15646420eb53c609a99c916877816d5000f@yahoo.com>

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