Bluetooth: Add support for ECDH test cases

This patch adds the test cases for ECDH cryptographic functionality
used by Bluetooth Low Energy Secure Connections feature.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/net/bluetooth/Kconfig b/net/bluetooth/Kconfig
index 3296841..8d3b607 100644
--- a/net/bluetooth/Kconfig
+++ b/net/bluetooth/Kconfig
@@ -77,4 +77,11 @@
 	  subsystem is compiled into the kernel image, then the test cases
 	  are run late in the initcall hierarchy.
 
+config BT_SELFTEST_ECDH
+	bool "ECDH test cases"
+	depends on BT_LE && BT_SELFTEST
+	help
+	  Run test cases for ECDH cryptographic functionality used by the
+	  Bluetooth Low Energy Secure Connections feature.
+
 source "drivers/bluetooth/Kconfig"