Force usage of MBEDTLS_PK_WRITE_C when PK_C and USE_PSA_CRYPTO is used

Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
diff --git a/include/mbedtls/build_info.h b/include/mbedtls/build_info.h
index cef6566..3dd944c 100644
--- a/include/mbedtls/build_info.h
+++ b/include/mbedtls/build_info.h
@@ -74,6 +74,9 @@
 #include MBEDTLS_USER_CONFIG_FILE
 #endif
 
+#if defined(MBEDTLS_PK_C) && defined(MBEDTLS_USE_PSA_CRYPTO)
+#define MBEDTLS_PK_WRITE_C
+#endif
 #if defined(MBEDTLS_PSA_CRYPTO_CONFIG)
 #include "mbedtls/config_psa.h"
 #endif