bootstage: Convert net progress numbers to enums

This changes over the network-related progress numbers to use enums
from bootstage.h.

Signed-off-by: Simon Glass <sjg@chromium.org>

common/env_common.c

@@ -228,7 +228,7 @@ void env_relocate(void)
 #if defined(CONFIG_ENV_IS_NOWHERE)	/* Environment not changable */
 		set_default_env(NULL);
 #else
-		show_boot_error(60);
+		show_boot_error(BOOTSTAGE_ID_NET_CHECKSUM);
 		set_default_env("!bad CRC");
 #endif
 	} else {