Add MODULE_LICENSE_PUBLIC_DOMAIN for the tzdata.

Change-Id: Ie3dd3daef4610f3bd4cbc60f1de854ad28189038
diff --git a/libc/zoneinfo/MODULE_LICENSE_PUBLIC_DOMAIN b/libc/zoneinfo/MODULE_LICENSE_PUBLIC_DOMAIN
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/libc/zoneinfo/MODULE_LICENSE_PUBLIC_DOMAIN