Bluetooth: controller: Update ISO Sync Terminate handling
Bluetooth: controller: Update ISO Sync Terminate handling

Update the ISO Synchronized Receiver Terminate and context
release handling to check for prepares in pipeline and
accordingly call lll_disable.

Signed-off-by: Vinayak Kariappa Chettimada <e780c9f87dc729ad454f47292ad82c8652353064@nordicsemi.no>

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