Bluetooth: controller: Add CTE present bit to pdu_data

If the CTE is attached to data channel packet, the packet must
include information about CTE. The information is stored in
CTEInfo structure that is available in S1 byte of a packet.
Radio checks if the S1 byte is present by verification of
CTE present (CP) bit in byte S0.

The commit add these data to pdu_data structure declaration.
That allows to prepare packet before it is parsed and send
by Radio peripheral.
Besides that there added a new function ull_pdu_data_init that
initlializes fields in pdu_data object that are read only by
lower link layer. CP bit in S0 byte and content of S1 bytes
are examples of such fields.

Signed-off-by: Piotr Pryga <piotr.pryga@nordicsemi.no>