Bluetooth: controller: Fix missing TIFS_HW cond. compilation

Fix a missing !CONFIG_BT_CTLR_TIFS_HW conditional
compilation when nRF52840 is configured to use hardware
Trx switching, that caused compile error.

Fixes: #5779
Fixes: #5761

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