RFR: 8294317: Insufficient build rules for tzdb.dat

[Naoto Sato]

The current makefile for `tzdb.dat` won't recompile if some dependent files (e.g. `VERSION`) are updated. Adding all files under the tzdb directory to the dependency will fix this issue.

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Commit messages:
 - 8294317: Insufficient build rules for tzdb.dat

Changes: https://git.openjdk.org/jdk/pull/10415/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10415&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8294317
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/10415.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10415/head:pull/10415

PR: https://git.openjdk.org/jdk/pull/10415