Bluetooth: Controller: revert to event callback inside radio ISR
Bluetooth: Controller: revert to event callback inside radio ISR

In order that host can continue a connection event by
enqueuing packets, the number of completed packets event
needs to be generated as soon it arrives on air. Hence, the
Controller now calls the radio_event_callback on every radio
Rx complete ISR.

The callback executes at the Radio ISR priority, take care
to only do as little as necessary in the callback, say, just
a semaphore give to wake up the hci_driver's thread.

Change-id: If48afd0f1390d450bc1e7ec66f1c9fd45208d9a4
Signed-off-by: Vinayak Chettimada <614d8484483ffac23eafa42e03839fd19b3e69b8@nordicsemi.no>

zephyriot/zephyr,sharronliu/zephyr,aceofall/zephyr-iotos,runchip/zephyr-cc3220,explora26/zephyr,pklazy/zephyr,fractalclone/zephyr-riscv,fbsder/zephyr,erwango/zephyr,tidyjiang8/zephyr-doc,bboozzoo/zephyr,mbolivar/zephyr,zephyriot/zephyr,galak/zephyr,sharronliu/zephyr,bboozzoo/zephyr,kraj/zephyr,Vudentz/zephyr,runchip/zephyr-cc3220,fbsder/zephyr,fractalclone/zephyr-riscv,rsalveti/zephyr,kraj/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,explora26/zephyr,nashif/zephyr,finikorg/zephyr,pklazy/zephyr,ldts/zephyr,nashif/zephyr,ldts/zephyr,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,bigdinotech/zephyr,ldts/zephyr,rsalveti/zephyr,aceofall/zephyr-iotos,nashif/zephyr,fractalclone/zephyr-riscv,bigdinotech/zephyr,Vudentz/zephyr,nashif/zephyr,kraj/zephyr,sharronliu/zephyr,bboozzoo/zephyr,runchip/zephyr-cc3200,bboozzoo/zephyr,erwango/zephyr,sharronliu/zephyr,aceofall/zephyr-iotos,galak/zephyr,zephyriot/zephyr,zephyrproject-rtos/zephyr,punitvara/zephyr,holtmann/zephyr,runchip/zephyr-cc3200,runchip/zephyr-cc3200,galak/zephyr,finikorg/zephyr,ldts/zephyr,pklazy/zephyr,galak/zephyr,holtmann/zephyr,galak/zephyr,punitvara/zephyr,tidyjiang8/zephyr-doc,runchip/zephyr-cc3200,mbolivar/zephyr,runchip/zephyr-cc3220,zephyrproject-rtos/zephyr,fbsder/zephyr,Vudentz/zephyr,zephyriot/zephyr,explora26/zephyr,punitvara/zephyr,explora26/zephyr,Vudentz/zephyr,punitvara/zephyr,GiulianoFranchetto/zephyr,tidyjiang8/zephyr-doc,holtmann/zephyr,mbolivar/zephyr,GiulianoFranchetto/zephyr,Vudentz/zephyr,tidyjiang8/zephyr-doc,bigdinotech/zephyr,aceofall/zephyr-iotos,sharronliu/zephyr,ldts/zephyr,aceofall/zephyr-iotos,runchip/zephyr-cc3200,runchip/zephyr-cc3220,GiulianoFranchetto/zephyr,GiulianoFranchetto/zephyr,kraj/zephyr,erwango/zephyr,fractalclone/zephyr-riscv,finikorg/zephyr,zephyriot/zephyr,tidyjiang8/zephyr-doc,zephyrproject-rtos/zephyr,mbolivar/zephyr,holtmann/zephyr,kraj/zephyr,rsalveti/zephyr,finikorg/zephyr,runchip/zephyr-cc3220,erwango/zephyr,bigdinotech/zephyr,holtmann/zephyr,fbsder/zephyr,bigdinotech/zephyr,fbsder/zephyr,nashif/zephyr,pklazy/zephyr,mbolivar/zephyr,rsalveti/zephyr,rsalveti/zephyr,explora26/zephyr,punitvara/zephyr,erwango/zephyr,Vudentz/zephyr,fractalclone/zephyr-riscv,pklazy/zephyr,bboozzoo/zephyr