roms: don't insert timeout.cfg

this is bloat, because it's something the user can already
do at runtime configuration anyway.

set it to a reasonable default of 8 seconds instead of 5,
and don't honour the timeout variable in target.cfg.

this will be documented in the next release.

Signed-off-by: Leah Rowe <leah@libreboot.org>

config/grub/default/config/payload

@@ -53,7 +53,7 @@ set default="0"
 if [ -f (cbfsdisk)/timeout.cfg ]; then
 	source (cbfsdisk)/timeout.cfg
 else	
-	set timeout=5
+	set timeout=8
 fi
 set grub_scan_disk="ahci ata"
 if [ -f (cbfsdisk)/scan.cfg ]; then