ARM: imx8mp: verdin-imx8mp: Add memory size detection

Add RAM auto-sizing, without this change memory size for all SKU is set
to 8GB and the system will crash on SKU with less memory as soon as the
non existent memory addresses are accessed.

Fixes: 2bc2f817cea7 ("board: toradex: add verdin imx8m plus support")
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Acked-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
diff --git a/board/toradex/verdin-imx8mp/verdin-imx8mp.c b/board/toradex/verdin-imx8mp/verdin-imx8mp.c
index 06f665b..9c2e44a 100644
--- a/board/toradex/verdin-imx8mp/verdin-imx8mp.c
+++ b/board/toradex/verdin-imx8mp/verdin-imx8mp.c
@@ -118,6 +118,16 @@
 	return 0;
 }
 
+int board_phys_sdram_size(phys_size_t *size)
+{
+	if (!size)
+		return -EINVAL;
+
+	*size = get_ram_size((void *)PHYS_SDRAM, PHYS_SDRAM_SIZE + PHYS_SDRAM_2_SIZE);
+
+	return 0;
+}
+
 #if IS_ENABLED(CONFIG_OF_LIBFDT) && IS_ENABLED(CONFIG_OF_BOARD_SETUP)
 int ft_board_setup(void *blob, struct bd_info *bd)
 {