Move RSA key generation code to the PSA RSA specific C file

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/library/psa_crypto_rsa.h b/library/psa_crypto_rsa.h
index 64013df..87e0a61 100644
--- a/library/psa_crypto_rsa.h
+++ b/library/psa_crypto_rsa.h
@@ -114,6 +114,29 @@
     const uint8_t *key_buffer, size_t key_buffer_size,
     uint8_t *data, size_t data_size, size_t *data_length );
 
+/**
+ * \brief Generate an RSA key.
+ *
+ * \note The signature of the function is that of a PSA driver generate_key
+ *       entry point.
+ *
+ * \param[in]  attributes         The attributes for the RSA key to generate.
+ * \param[out] key_buffer         Buffer where the key data is to be written.
+ * \param[in]  key_buffer_size    Size of \p key_buffer in bytes.
+ * \param[out] key_buffer_length  On success, the number of bytes written in
+ *                                \p key_buffer.
+ *
+ * \retval #PSA_SUCCESS
+ *         The key was successfully generated.
+ * \retval #PSA_ERROR_NOT_SUPPORTED
+ *         Key length or type not supported.
+ * \retval #PSA_ERROR_BUFFER_TOO_SMALL
+ *         The size of \p key_buffer is too small.
+ */
+psa_status_t mbedtls_psa_rsa_generate_key(
+    const psa_key_attributes_t *attributes,
+    uint8_t *key_buffer, size_t key_buffer_size, size_t *key_buffer_length );
+
 /*
  * BEYOND THIS POINT, TEST DRIVER ENTRY POINTS ONLY.
  */