kconfig: handle P_SYMBOL in print_symbol()

Each symbol has a property of type P_SYMBOL since commit
59e89e3d (kconfig: save location of config symbols).
Handle those properties in print_symbol().

Further, place a pointer to print_symbol() in the comment above the
list of known property type.
Signed-off-by: NDirk Gouders <dirk@gouders.net>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

scripts/kconfig/expr.h

@@ -171,6 +171,9 @@ struct symbol {
  * config BAZ
  *         int "BAZ Value"
  *         range 1..255
+ *
+ * Please, also check zconf.y:print_symbol() when modifying the
+ * list of property types!
  */
 enum prop_type {
 	P_UNKNOWN,

scripts/kconfig/zconf.y

@@ -717,6 +717,10 @@ static void print_symbol(FILE *out, struct menu *menu)
 			print_quoted_string(out, prop->text);
 			fputc('\n', out);
 			break;
+		case P_SYMBOL:
+			fputs( "  symbol ", out);
+			fprintf(out, "%s\n", prop->sym->name);
+			break;
 		default:
 			fprintf(out, "  unknown prop %d!\n", prop->type);
 			break;