Add missing MBEDTLS_PSA_BUILTIN for ChaCha20-Poly1305

Add these missing definitions when this configration is chosen.

Signed-off-by: David Brown <david.brown@linaro.org>
diff --git a/include/mbedtls/config_psa.h b/include/mbedtls/config_psa.h
index b085500..1e63872 100644
--- a/include/mbedtls/config_psa.h
+++ b/include/mbedtls/config_psa.h
@@ -353,6 +353,7 @@
 #if defined(PSA_WANT_ALG_CHACHA20_POLY1305)
 #if defined(PSA_WANT_KEY_TYPE_CHACHA20)
 #define MBEDTLS_CHACHAPOLY_C
+#define MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305 1
 #else /* not PSA_WANT_KEY_TYPE_CHACHA20 */
 // #error "PSA_WANT_ALG_CHACHA20_POLY1305 requires PSA_WANT_KEY_TYPE_CHACHA20"
 #endif /* PSA_WANT_KEY_TYPE_CHACHA20 */
@@ -495,6 +496,7 @@
 #define MBEDTLS_PSA_BUILTIN_ALG_STREAM_CIPHER 1
 #if defined(MBEDTLS_CHACHAPOLY_C)
 #define PSA_WANT_ALG_CHACHA20_POLY1305 1
+#define MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305 1
 #endif
 #endif