Modify config option for SHA384.

Although SHA512 is currently required to enable SHA384, this
is expected to change in the future. This commit is an
intermediate step towards fully separating SHA384 and SHA512.

check_config is the only module which enforces that SHA512 is
enabled together with SHA384.

Signed-off-by: Mateusz Starzyk <mateusz.starzyk@mobica.com>
diff --git a/configs/config-symmetric-only.h b/configs/config-symmetric-only.h
index 8a289cd..28150d6 100644
--- a/configs/config-symmetric-only.h
+++ b/configs/config-symmetric-only.h
@@ -86,6 +86,7 @@
 #define MBEDTLS_SHA1_C
 #define MBEDTLS_SHA256_C
 #define MBEDTLS_SHA512_C
+#define MBEDTLS_SHA384_C
 //#define MBEDTLS_THREADING_C
 #define MBEDTLS_TIMING_C
 #define MBEDTLS_VERSION_C