Bluetooth: controller: Fix Conn Param Req procedure stall issue

Fix an issue wherein local or remote initiated Connection
Parameter Request procedure would stall without generation
of LE Connection Update Complete HCI event because a local
or remote initiated PHY Update procedure has overwritten the
currently active Link Layer Control Procedure type.

Signed-off-by: Vinayak Kariappa Chettimada <vinayak.kariappa@gmail.com>