[U-Boot] CONFIG_BOOTDELAY and env_default.h

[Alex Kiernan]

I've just been digging into a problem where I've got both
CONFIG_ENV_IS_NOWHERE set and CONFIG_BOOTDELAY set to -2 and it turns
out in env_default.h we have:

#if defined(CONFIG_BOOTDELAY) && (CONFIG_BOOTDELAY >= 0)
        "bootdelay="    __stringify(CONFIG_BOOTDELAY)   "\0"
#endif

So the -ve values never make it into the default environment, which
means I don't have it at all when CONFIG_ENV_IS_NOWHERE.

The (CONFIG_BOOTDELAY >= 0) seems to have been there forever
(c609719b8d1b2dca590e0ed499016d041203e403, Sun Nov 3 00:24:07 2002
+0000 is as far back as I've gone), but we've then changed the
behaviours of the bootdelay values in (the commit I was looking at was
2fbb8462b0e18893b4b739705db047ffda82d4fc from Mon Jun 27 16:23:01 2016
+0900, but I'm not sure that's really the right one)

I think we should change the code to a simple #if defined(CONFIG_BOOTDELAY)

?

-- 
Alex Kiernan