kconfig: handle P_SYMBOL in print_symbol()

Each symbol has a property of type P_SYMBOL since commit
59e89e3ddf85 (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: Dirk Gouders <dirk@gouders.net>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/scripts/kconfig/zconf.y b/scripts/kconfig/zconf.y
index ed84d4a..4b68272 100644
--- a/scripts/kconfig/zconf.y
+++ b/scripts/kconfig/zconf.y
@@ -717,6 +717,10 @@
 			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;