Bluetooth: Controller: llcp: Add missing CTE pause in remote PHY change

There were missing pause of CTE request in case remote PHY change
was handled. That may end in violation of BT 5.3 Core Vol 6, Part B
section 5.1.10.1 Packet transmission restrictions.
Without the change there was a possibility to transmitt CTE when
PHY is about to change to PHY CODED.

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