Add a tool to add keys to keyring.

This CL adds a binary to load keys to a keyring.

Bug: 112038861
Test: mini-keyctl -k .fsverity -c PATH_CONTAINER_CERTS
Test: cat /proc/keys and find the newly added keys
Change-Id: Iead68618ea194e9412616c5c6cff885e3cf78520
diff --git a/libkeyutils/include/keyutils.h b/libkeyutils/include/keyutils.h
index 585767d..c508f27 100644
--- a/libkeyutils/include/keyutils.h
+++ b/libkeyutils/include/keyutils.h
@@ -51,6 +51,10 @@
 
 long keyctl_unlink(key_serial_t key, key_serial_t keyring);
 
+long keyctl_restrict_keyring(key_serial_t keyring, const char* type, const char* restriction);
+
+long keyctl_get_security(key_serial_t key, char* buffer, size_t buflen);
+
 __END_DECLS
 
 #endif