Rename "key generation method" to "key production parameters"

"Key generation method" was misleading since it also applies to key
derivation. Change "key generation" to "key production", which we aren't
using yet and has roughly the right intuition. Change "method" to
"parameters" which there seems to be a slight preference for. Discussion
thread: https://github.com/Mbed-TLS/mbedtls/pull/8815#discussion_r1486524295

Identifiers renamed:
psa_key_generation_method_t → psa_key_production_parameters_t
psa_key_generation_method_s → psa_key_production_parameters_s
PSA_KEY_GENERATION_METHOD_INIT → PSA_KEY_PRODUCTION_PARAMETERS_INIT
method → params
method_data_length → params_data_length
default_method → default_production_parameters
psa_key_generation_method_is_default → psa_key_production_parameters_are_default
setup_key_generation_method → setup_key_production_parameters
key_generation_method_init → key_production_parameters_init

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/include/psa/crypto_struct.h b/include/psa/crypto_struct.h
index f41bc83..e2068e8 100644
--- a/include/psa/crypto_struct.h
+++ b/include/psa/crypto_struct.h
@@ -223,21 +223,21 @@
     return v;
 }
 
-struct psa_key_generation_method_s {
+struct psa_key_production_parameters_s {
     /* Future versions may add other fields in this structure. */
     uint32_t flags;
     uint8_t data[];
 };
 
-/** The default method for key generation or key derivation.
+/** The default production parameters for key generation or key derivation.
  *
  * Calling psa_generate_key_ext() or psa_key_derivation_output_key_ext()
- * with `method=PSA_KEY_GENERATION_METHOD_INIT` and
- * `method_data_length == 0` is equivalent to
+ * with `params=PSA_KEY_PRODUCTION_PARAMETERS_INIT` and
+ * `params_data_length == 0` is equivalent to
  * calling psa_generate_key() or psa_key_derivation_output_key()
  * respectively.
  */
-#define PSA_KEY_GENERATION_METHOD_INIT { 0 }
+#define PSA_KEY_PRODUCTION_PARAMETERS_INIT { 0 }
 
 struct psa_key_policy_s {
     psa_key_usage_t MBEDTLS_PRIVATE(usage);