board: toradex: add Toradex SMARC iMX8MP

Add support for the Toradex SMARC iMX8MP.

Link: https://www.toradex.com/computer-on-modules/smarc-arm-family/nxp-imx-8m-plus
Link: https://www.toradex.com/products/carrier-board/smarc-development-board-kit
Signed-off-by: Vitor Soares <vitor.soares@toradex.com>
diff --git a/board/toradex/smarc-imx8mp/lpddr4_timing.h b/board/toradex/smarc-imx8mp/lpddr4_timing.h
new file mode 100644
index 0000000..f61789c
--- /dev/null
+++ b/board/toradex/smarc-imx8mp/lpddr4_timing.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (C) 2024 Toradex */
+
+#ifndef __LPDDR4_TIMING_H__
+#define __LPDDR4_TIMING_H__
+
+void lpddr4_single_rank_training_patch(void);
+
+#endif /* __LPDDR4_TIMING_H__ */