psa: Extend psa_get_key_buffer_size scope

When generating transparent keys, we need to be able
to compute the size of the key buffer whether the
key is generated by the Mbed TLS library or by an
accelerator. Thus, change the RSA/ECP
MBEDTLS_PSA_BUILTIN_... compilation guards with
their PSA_WANT_... counterparts.

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 67fdd5c..0f7d4bd 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -6013,7 +6013,7 @@
         *key_buffer_size = PSA_BITS_TO_BYTES( bits );
     }
     else
-#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR)
+#if defined(PSA_WANT_KEY_TYPE_RSA_KEY_PAIR)
     if( PSA_KEY_TYPE_IS_RSA( type ) && PSA_KEY_TYPE_IS_KEY_PAIR( type ) )
     {
         if( bits > PSA_VENDOR_RSA_MAX_KEY_BITS )
@@ -6027,15 +6027,15 @@
         *key_buffer_size = PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE( bits );
     }
     else
-#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) */
+#endif /* defined(PSA_WANT_KEY_TYPE_RSA_KEY_PAIR) */
 
-#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR)
+#if defined(PSA_WANT_KEY_TYPE_ECC_KEY_PAIR)
     if( PSA_KEY_TYPE_IS_ECC( type ) && PSA_KEY_TYPE_IS_KEY_PAIR( type ) )
     {
         *key_buffer_size = PSA_BITS_TO_BYTES( bits );
     }
     else
-#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) */
+#endif /* defined(PSA_WANT_KEY_TYPE_ECC_KEY_PAIR) */
     {
         return( PSA_ERROR_NOT_SUPPORTED );
     }