stm32mp1: ram: add tuning in DDR interactive mode

Add command tuning for DDR interactive mode, used during
board bring-up or with CubeMX DDR tools to execute software
tuning for the DDR configuration:
- software read DQS Gating (replace the built-in one)
- Bit de-skew
- Eye Training or DQS training

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/drivers/ram/stm32mp1/stm32mp1_tests.h b/drivers/ram/stm32mp1/stm32mp1_tests.h
index 8436780..55f5d6d 100644
--- a/drivers/ram/stm32mp1/stm32mp1_tests.h
+++ b/drivers/ram/stm32mp1/stm32mp1_tests.h
@@ -28,4 +28,7 @@
 extern const struct test_desc test[];
 extern const int test_nb;
 
+extern const struct test_desc tuning[];
+extern const int tuning_nb;
+
 #endif