localmodconfig: Fix whitespace repeat count after "tristate"

Also recognize standalone "prompt".

Before this patch we incorrectly identified some symbols as not having a
prompt and potentially needing to be selected by something else.

Note that this patch could theoretically change the resulting .config,
causing it to have fewer symbols turned on. However, given the current set
of Kconfig files, this situation does not occur because the symbols newly
added to %prompts are absent from %selects.

Link: http://lkml.kernel.org/r/1461696998-3953-1-git-send-email-bpoirier@suse.com

Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

scripts/kconfig/streamline_config.pl

@@ -237,7 +237,7 @@ sub read_kconfig {
 	    }
 
 	# configs without prompts must be selected
-	} elsif ($state ne "NONE" && /^\s*tristate\s\S/) {
+	} elsif ($state ne "NONE" && /^\s*(tristate\s+\S|prompt\b)/) {
 	    # note if the config has a prompt
 	    $prompts{$config} = 1;