[nrf fromtree] net: openthread: Fix missing dependency for OT diag.

Commit fixes missing dependency for `ot diag cw` command for nrf5xx
by adding default vale to `NRF_802154_CARRIER_FUNCTIONS`.

Signed-off-by: Przemyslaw Bida <przemyslaw.bida@nordicsemi.no>
(cherry picked from commit a923a4a)

modules/hal_nordic/Kconfig

@@ -204,6 +204,7 @@ config NRF_802154_SECURITY_KEY_STORAGE_SIZE
 
 config NRF_802154_CARRIER_FUNCTIONS
 	bool "nRF 802.15.4 carrier functions"
+	default y if OPENTHREAD_DIAG
 	help
 	  This option enables functions such as modulated carrier and continuous carrier.
 	  If this option is modified on a multicore SoC, its remote counterpart must be set to the exact same value.