[dice] Move DiceGenerateCertificate nostd/std versions to diced_open_dice

As a step of merging the existing diced_open_dice_cbor library into
the new open-dice wrapper diced_open_dice.

Bug: 267575445
Test: atest diced_utils_test diced_sample_inputs_test \
diced_vendor_test diced_open_dice_cbor_test \
libdiced_open_dice_nostd.integration_test \
libdiced_open_dice.integration_test diced_open_dice_cbor_test

Change-Id: Id50648f12be6cb236e8ea268bbbe791a30d5269b
diff --git a/diced/open_dice/src/lib.rs b/diced/open_dice/src/lib.rs
index f76494e..7e8c59a 100644
--- a/diced/open_dice/src/lib.rs
+++ b/diced/open_dice/src/lib.rs
@@ -34,9 +34,9 @@
     HIDDEN_SIZE, ID_SIZE, PRIVATE_KEY_SEED_SIZE,
 };
 pub use error::{check_result, DiceError, Result};
-pub use ops::{hash, kdf};
+pub use ops::{generate_certificate, hash, kdf};
 #[cfg(feature = "std")]
 pub use retry::{
     retry_bcc_format_config_descriptor, retry_bcc_main_flow, retry_dice_main_flow,
-    OwnedDiceArtifacts,
+    retry_generate_certificate, OwnedDiceArtifacts,
 };