Bluetooth: Controller: Add Long Control PDU support

Add long control PDU size support, also the implementation
now allocates control PDU size restricted to the supported
biggest control PDU that is enabled in the application
build. Features that are covered based on the increasing
control PDU sizes are ClearText connections, Encrypted
Connections, Connection Parameter Request support and
Create CIS control Procedure (Connected Central ISO)
support.

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