bluetooth: controller: Only BT_CTLR_ECDH default y if BT_HCI_RAW

In zephyrproject-rtos#84268
the ability to use the controller for ECDH was removed from
the host.

This means that BT_CTLR_ECDH is now only useful when using
BT_HCI_RAW.

(cherry picked from commit 706938d)

Original-Signed-off-by: Sean Madigan <[email protected]>
GitOrigin-RevId: 706938d
Cr-Build-Id: 8723822246285105201
Cr-Build-Url: https://cr-buildbucket.appspot.com/build/8723822246285105201
Copybot-Job-Name: zephyr-main-copybot-downstream
Change-Id: Ic0840ec7b9b2a9510051410509eace6250a41ee4
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/zephyr/+/6231798
Tested-by: Jeremy Bettis <[email protected]>
Tested-by: ChromeOS Prod (Robot) <[email protected]>
Commit-Queue: Jeremy Bettis <[email protected]>
Reviewed-by: Jeremy Bettis <[email protected]>

Author: Sean Madigan

subsys/bluetooth/controller/Kconfig

@@ -550,7 +550,7 @@ config BT_CTLR_LE_ENC
 config BT_CTLR_ECDH
 	bool "Elliptic Curve Diffie-Hellman (ECDH)"
 	depends on BT_CTLR_ECDH_SUPPORT
-	default y
+	default y if BT_HCI_RAW
 	help
 	  Enable support for Bluetooth v4.2 Elliptic Curve Diffie-Hellman
 	  feature in the controller.