Bluetooth: controller: Fix HCI LE Set PHY command status response

Fixed the implementation to generate command status as per
Bluetooth v5.0 specification instead of the incorrect
command complete that was generated before.

Also, the unsupported features status will be generated
before the invalid parameters status.

Relates to commit 258c7ccf ("Bluetooth: controller: Fix
HCI LE Set PHY invalid behavior check")

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