Correctly use new path to js_protocol.pdl

TBR=pfeldman@chromium.org

Bug: v8:9247
Change-Id: Icda672d6add5f4ff522706c8c4cb0f907bcff1b4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1666991Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62271}

src/inspector/inspector_protocol_config.json

 {
     "protocol": {
-        "path": "js_protocol.pdl",
+        "path": "../../include/js_protocol.pdl",
         "package": "src/inspector/protocol",
         "output": "protocol",
         "namespace": ["v8_inspector", "protocol"],