Add third_party/cpu_features license path.

This should fix current chromium roll issue:
https://ci.chromium.org/ui/p/webrtc/builders/try/android_arm_rel/51083/overview

Change-Id: I0db870c7f390b0a7f067b18d33096120b1c861fa
Bug: None
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/307300
Commit-Queue: Jeremy Leconte <jleconte@google.com>
Reviewed-by: Björn Terelius <terelius@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#40193}

tools_webrtc/libs/generate_licenses.py

@@ -42,6 +42,7 @@ LIB_TO_LICENSES_DICT = {
     ],
     'boringssl': ['third_party/boringssl/src/LICENSE'],
     'crc32c': ['third_party/crc32c/src/LICENSE'],
+    'cpu_features': ['third_party/cpu_features/src/LICENSE'],
     'dav1d': ['third_party/dav1d/LICENSE'],
     'errorprone': [
         'third_party/android_deps/libs/'