Enable fallocate in defconfig.
diff --git a/toys/other/fallocate.c b/toys/other/fallocate.c
index 22ef978..0144025 100644
--- a/toys/other/fallocate.c
+++ b/toys/other/fallocate.c
@@ -8,7 +8,7 @@
 
 config FALLOCATE
   bool "fallocate"
-  default n
+  default y
   help
     usage: fallocate [-l size] file