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/apalis-imx8/apalis-imx8.c b/board/toradex/apalis-imx8/apalis-imx8.c
index e2bbaba..b351ce6 100644
--- a/board/toradex/apalis-imx8/apalis-imx8.c
+++ b/board/toradex/apalis-imx8/apalis-imx8.c
@@ -215,7 +215,7 @@
 	build_info();
 	print_bootinfo();
 
-	return 0;
+	return tdx_checkboard();
 }
 
 static enum pcb_rev_t get_pcb_revision(void)