Bluetooth: move ecdh allocation outside of ecdh_helper

Before this change, a new crypto tfm was allocated, each time,
for both key generation and shared secret computation.

Allocate a single tfm for both cases.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/net/bluetooth/ecdh_helper.h b/net/bluetooth/ecdh_helper.h
index 7a423fa..5cde37d 100644
--- a/net/bluetooth/ecdh_helper.h
+++ b/net/bluetooth/ecdh_helper.h
@@ -20,8 +20,10 @@
  * COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
  * SOFTWARE IS DISCLAIMED.
  */
+#include <crypto/kpp.h>
 #include <linux/types.h>
 
-bool compute_ecdh_secret(const u8 pub_a[64], const u8 priv_b[32],
-			 u8 secret[32]);
-bool generate_ecdh_keys(u8 public_key[64], u8 private_key[32]);
+bool compute_ecdh_secret(struct crypto_kpp *tfm, const u8 pub_a[64],
+			 const u8 priv_b[32], u8 secret[32]);
+bool generate_ecdh_keys(struct crypto_kpp *tfm, u8 public_key[64],
+			u8 private_key[32]);