Bluetooth: AMP: Add AMP key calculation

Function calculates AMP keys using hmac_sha256 helper. Calculated keys
are Generic AMP Link Key (gamp) and Dedicated AMP Link Key with
keyID "802b" for 802.11 PAL.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
diff --git a/net/bluetooth/Kconfig b/net/bluetooth/Kconfig
index 3537d38..1c11d0d 100644
--- a/net/bluetooth/Kconfig
+++ b/net/bluetooth/Kconfig
@@ -11,6 +11,7 @@
 	select CRYPTO_BLKCIPHER
 	select CRYPTO_AES
 	select CRYPTO_ECB
+	select CRYPTO_SHA256
 	help
 	  Bluetooth is low-cost, low-power, short-range wireless technology.
 	  It was designed as a replacement for cables and other short-range