main: Drop show_boot_progress() prototype

This is defined in bootstage.h and is not called in this file anyway. Drop
it.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>

common/main.c

@@ -15,11 +15,6 @@
 #include <init.h>
 #include <version.h>
 
-/*
- * Board-specific Platform code can reimplement show_boot_progress () if needed
- */
-__weak void show_boot_progress(int val) {}
-
 static void run_preboot_environment_command(void)
 {
 	char *p;