Bluetooth: controller: Internal document purpose of end capture
Bluetooth: controller: Internal document purpose of end capture

Document internal the purposes of various Tx/Rx PDU end
capture setup.

Also, removed any redundant capture of packet end.

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

ldts/zephyr,GiulianoFranchetto/zephyr,zephyriot/zephyr,zephyriot/zephyr,kraj/zephyr,nashif/zephyr,fbsder/zephyr,punitvara/zephyr,zephyriot/zephyr,nashif/zephyr,kraj/zephyr,mbolivar/zephyr,zephyrproject-rtos/zephyr,explora26/zephyr,mbolivar/zephyr,finikorg/zephyr,zephyriot/zephyr,fbsder/zephyr,finikorg/zephyr,mbolivar/zephyr,punitvara/zephyr,galak/zephyr,aceofall/zephyr-iotos,Vudentz/zephyr,explora26/zephyr,explora26/zephyr,Vudentz/zephyr,punitvara/zephyr,galak/zephyr,galak/zephyr,kraj/zephyr,fbsder/zephyr,punitvara/zephyr,GiulianoFranchetto/zephyr,zephyrproject-rtos/zephyr,aceofall/zephyr-iotos,GiulianoFranchetto/zephyr,finikorg/zephyr,Vudentz/zephyr,kraj/zephyr,fbsder/zephyr,GiulianoFranchetto/zephyr,punitvara/zephyr,zephyrproject-rtos/zephyr,aceofall/zephyr-iotos,explora26/zephyr,zephyriot/zephyr,Vudentz/zephyr,mbolivar/zephyr,aceofall/zephyr-iotos,ldts/zephyr,finikorg/zephyr,ldts/zephyr,finikorg/zephyr,ldts/zephyr,kraj/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,aceofall/zephyr-iotos,Vudentz/zephyr,nashif/zephyr,galak/zephyr,galak/zephyr,nashif/zephyr,fbsder/zephyr,explora26/zephyr,zephyrproject-rtos/zephyr,mbolivar/zephyr,nashif/zephyr,ldts/zephyr,GiulianoFranchetto/zephyr