[rkp] Add request/response for ECDSA P256 key pair generation

This cl adds the request and response protocol for the ECDSA P256
key pair generation needed for the IRemotelyProvisionedComponent
implementation.

Bug: 299055662
Test: atest rialto_test
Change-Id: Ib3b8519e3833a6617fc6daa878777b9e0499f751
diff --git a/rialto/src/requests/mod.rs b/rialto/src/requests/mod.rs
index ca22777..2ed568c 100644
--- a/rialto/src/requests/mod.rs
+++ b/rialto/src/requests/mod.rs
@@ -15,5 +15,6 @@
 //! This module contains functions for the request processing.
 
 mod api;
+mod rkp;
 
 pub use api::process_request;