kconfig: add defconfig_list/module option

This makes it possible to change two options which were hardcoded sofar.
1. Any symbol can now take the role of CONFIG_MODULES
2. The more useful option is to change the list of default file names,
   which kconfig uses to load the base configuration if .config isn't
   available.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c
index 151ef21..a8afce2 100644
--- a/scripts/kconfig/menu.c
+++ b/scripts/kconfig/menu.c
@@ -154,6 +154,20 @@
 
 void menu_add_option(int token, char *arg)
 {
+	struct property *prop;
+
+	switch (token) {
+	case T_OPT_MODULES:
+		prop = prop_alloc(P_DEFAULT, modules_sym);
+		prop->expr = expr_alloc_symbol(current_entry->sym);
+		break;
+	case T_OPT_DEFCONFIG_LIST:
+		if (!sym_defconfig_list)
+			sym_defconfig_list = current_entry->sym;
+		else if (sym_defconfig_list != current_entry->sym)
+			zconf_error("trying to redefine defconfig symbol");
+		break;
+	}
 }
 
 static int menu_range_valid_sym(struct symbol *sym, struct symbol *sym2)