Bluetooth: controller: legacy: Validate chan map and hop value

Add validation of channel map and hop increment value
received in CONNECT_IND PDU.

Zero bit count leads to controller assert or divide-by-zero
fault.

Hop increment shall be between 5 and 16 by BT Specification.

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