toradex: Use checkboard() instead of show_board_info()

Boards can use a sysinfo driver if a particular model name is needed.
Update this board to use checkboard() directly, rather than having a
weak function laid on top of a weak function.

Make all the checkboard() functions call the new tdx_checkboard() so
that the same information is displayed.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/board/toradex/colibri_imx6/colibri_imx6.c b/board/toradex/colibri_imx6/colibri_imx6.c
index e6c9b10..7635c58 100644
--- a/board/toradex/colibri_imx6/colibri_imx6.c
+++ b/board/toradex/colibri_imx6/colibri_imx6.c
@@ -649,7 +649,8 @@
 	printf("Model: Toradex Colibri iMX6 %s %sMB%s\n",
 	       is_cpu_type(MXC_CPU_MX6DL) ? "DualLite" : "Solo",
 	       (gd->ram_size == 0x20000000) ? "512" : "256", it);
-	return 0;
+
+	return tdx_checkboard();
 }
 
 #if defined(CONFIG_OF_LIBFDT) && defined(CONFIG_OF_BOARD_SETUP)