kconfig: attach help text to menus

Roman Zippel wrote:
> A simple example would be
> help texts, right now they are per symbol, but they should really be per
> menu, so archs can provide different help texts for something.

This patch does this and at the same time introduce a few API
funtions used to access the help text.

The relevant api functions are introduced in the various frontends.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
diff --git a/scripts/kconfig/gconf.c b/scripts/kconfig/gconf.c
index 61d8166..262908c 100644
--- a/scripts/kconfig/gconf.c
+++ b/scripts/kconfig/gconf.c
@@ -38,9 +38,6 @@
 static gboolean show_debug = FALSE;
 static gboolean resizeable = FALSE;
 
-static char nohelp_text[] =
-    N_("Sorry, no help available for this option yet.\n");
-
 GtkWidget *main_wnd = NULL;
 GtkWidget *tree1_w = NULL;	// left  frame
 GtkWidget *tree2_w = NULL;	// right frame
@@ -462,12 +459,9 @@
 	GtkTextIter start, end;
 	const char *prompt = menu_get_prompt(menu);
 	gchar *name;
-	const char *help = _(nohelp_text);
+	const char *help;
 
-	if (!menu->sym)
-		help = "";
-	else if (menu->sym->help)
-		help = _(menu->sym->help);
+	help = _(menu_get_help(menu));
 
 	if (menu->sym && menu->sym->name)
 		name = g_strdup_printf(_(menu->sym->name));