Fix config-mini-tls1_1 PK_WRITE requirement when USA_PSA_CRYPTO is used

Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
diff --git a/configs/config-mini-tls1_1.h b/configs/config-mini-tls1_1.h
index afa5cc8..9092829 100644
--- a/configs/config-mini-tls1_1.h
+++ b/configs/config-mini-tls1_1.h
@@ -76,6 +76,10 @@
 //#define MBEDTLS_USE_PSA_CRYPTO
 //#define MBEDTLS_PSA_CRYPTO_C
 
+/* With MBEDTLS_PSA_CRYPTO_C, importing an RSA key requires MBEDTLS_PK_WRITE_C */
+#if defined(MBEDTLS_PSA_CRYPTO_C)
+#define MBEDTLS_PK_WRITE_C
+#endif
 #include "mbedtls/check_config.h"
 
 #endif /* MBEDTLS_CONFIG_H */