Rename generator-related internal identifiers

    perl -pe 's/crypto_generator/key_derivation/gi' $(git ls-files)
    perl -pe 's/_generator/_key_derivation/gi' $(git ls-files)
diff --git a/include/psa/crypto.h b/include/psa/crypto.h
index 0bff6ce..17af57d 100644
--- a/include/psa/crypto.h
+++ b/include/psa/crypto.h
@@ -3002,7 +3002,7 @@
  * make any assumptions about the content of this structure except
  * as directed by the documentation of a specific implementation.
  */
-typedef struct psa_crypto_generator_s psa_key_derivation_operation_t;
+typedef struct psa_key_derivation_s psa_key_derivation_operation_t;
 
 /** \def PSA_KEY_DERIVATION_OPERATION_INIT
  *