meson: 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.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
diff --git a/arch/arm/mach-meson/board-info.c b/arch/arm/mach-meson/board-info.c
index 2421acd..95a29da 100644
--- a/arch/arm/mach-meson/board-info.c
+++ b/arch/arm/mach-meson/board-info.c
@@ -168,7 +168,7 @@
 	return socinfo;
 }
 
-int show_board_info(void)
+int checkboard(void)
 {
 	unsigned int socinfo;