encrypted-keys: remove trusted-keys dependency

Encrypted keys are decrypted/encrypted using either a trusted-key or,
for those systems without a TPM, a user-defined key.  This patch
removes the trusted-keys and TCG_TPM dependencies.

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
diff --git a/security/keys/encrypted-keys/encrypted.h b/security/keys/encrypted-keys/encrypted.h
index cef5e2f..b6ade89 100644
--- a/security/keys/encrypted-keys/encrypted.h
+++ b/security/keys/encrypted-keys/encrypted.h
@@ -2,6 +2,17 @@
 #define __ENCRYPTED_KEY_H
 
 #define ENCRYPTED_DEBUG 0
+#ifdef CONFIG_TRUSTED_KEYS
+extern struct key *request_trusted_key(const char *trusted_desc,
+				       u8 **master_key, size_t *master_keylen);
+#else
+static inline struct key *request_trusted_key(const char *trusted_desc,
+					      u8 **master_key,
+					      size_t *master_keylen)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
+#endif
 
 #if ENCRYPTED_DEBUG
 static inline void dump_master_key(const u8 *master_key, size_t master_keylen)